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Title: Laser Filamentation - Beyond Self-focusing and Plasma Defocusing.
Creator: Lim, Khan, Richardson, Martin, Chang, Zenghu, Christodoulides, Demetrios, Zhang, Xi-Cheng, University of Central Florida
Abstract / Description: Laser filamentation is a highly complex and dynamic nonlinear process that is sensitive to many physical parameters. The basic properties that define a filament consist of (i) a narrow, high intensity core that persists for distances much greater than the Rayleigh distance, (ii) a low density plasma channel existing within the filament core, and (iii) a supercontinuum generated over the course of filamentation. However, there remain many questions pertaining to how these basic properties are...
Show moreLaser filamentation is a highly complex and dynamic nonlinear process that is sensitive to many physical parameters. The basic properties that define a filament consist of (i) a narrow, high intensity core that persists for distances much greater than the Rayleigh distance, (ii) a low density plasma channel existing within the filament core, and (iii) a supercontinuum generated over the course of filamentation. However, there remain many questions pertaining to how these basic properties are affected by changes in the conditions in which the filaments are formed; that is the premise of the work presented in this dissertation.To examine the effects of anomalous dispersion and of different multi-photon ionization regimes, filaments were formed in solids with different laser wavelengths. The results provided a better understanding of supercontinuum generation in the anomalous dispersion regime, and of how multi-photon ionization can affect the formation of filaments.Three different experiments were carried out on filamentation in air. The first was an investigation into the effects of geometrical focusing. A simplified theoretical model was derived to determine the transition of filamentation in the linear-focusing and nonlinear- focusing regimes. The second examined the effects of polarization on supercontinuum generation, where a polarization-dependent anomalous spectral broadening phenomenon due to molecular effects was identified. The third involved the characterization of filaments in the ultraviolet. The combination of physical mechanisms responsible for filamentation in the ultraviolet was found to be different from that in the near infrared.
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Date Issued: 2014
Identifier: CFE0005520, ucf:50317
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005520

Title: Third Order Nonlinearity of Organic Molecules.
Creator: Hu, Honghua, Vanstryland, Eric, Hagan, David, Zeldovich, Boris, Hernandez, Florencio, University of Central Florida
Abstract / Description: The main goal of this dissertation is to investigate the third-order nonlinearity of organic molecules. This topic contains two aspects: two-photon absorption (2PA) and nonlinear refraction (NLR), which are associated with the imaginary and real part of the third-order nonlinearity (?(3)) of the material, respectively. With the optical properties tailored through meticulous molecular structure engineering, organic molecules are promising candidates to exhibit large third-order nonlinearities....
Show moreThe main goal of this dissertation is to investigate the third-order nonlinearity of organic molecules. This topic contains two aspects: two-photon absorption (2PA) and nonlinear refraction (NLR), which are associated with the imaginary and real part of the third-order nonlinearity (?(3)) of the material, respectively. With the optical properties tailored through meticulous molecular structure engineering, organic molecules are promising candidates to exhibit large third-order nonlinearities. Both linear (absorption, fluorescence, fluorescence excitation anisotropy) and nonlinear (Z-scan, two-photon fluorescence, pump-probe) techniques are described and utilized to fully characterize the spectroscopic properties of organic molecules in solution or solid-state form. These properties are then analyzed by quantum chemical calculations or other specific quantum mechanical model to understand the origins of the nonlinearities as well as the correlations with their unique molecular structural features. These calculations are performed by collaborators. The 2PA study of organic materials is focused on the structure-2PA property relationships of four groups of dyes with specific molecular design approaches as the following: (1) Acceptor-?-Acceptor dyes for large 2PA cross section, (2) Donor-?-Acceptor dyes for strong solvatochromic effects upon the 2PA spectra, (3) Near-infrared polymethine dyes for a symmetry breaking effect, (4) Sulfur-squaraines vs. oxygen-squaraines to study the role of sulfur atom replacement upon their 2PA spectra. Additionally, the 2PA spectrum of a solid-state single crystal made from a Donor-?-Acceptor dye is measured, and the anisotropic nonlinearity is studied with respect to different incident polarizations. These studies further advance our understanding towards an ultimate goal to a predictive capability for the 2PA properties of organic molecules. The NLR study on molecules is focused on the temporal and spectral dispersion of the nonlinear refraction index, n2, of the molecules. Complicated physical mechanisms, originating from either electronic transitions or nuclei movement, are introduced in general. By adopting a prism compressor / stretcher to control the pulsewidth, an evolution of n2 with respect to incident pulsewidth is measured on a simple inorganic molecule (-)carbon disulfide (CS2) in neat liquid at 700 nm and 1064 nm to demonstrate the pulsewidth dependent nonlinear refraction. The n2 spectra of CS2 and certain organic molecules are measured by femtosecond pulses, which are then analyzed by a 3-level model, a simplified (")Sum-over-states(") quantum mechanical model. These studies can serve as a precursor for future NLR investigations.
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Date Issued: 2012
Identifier: CFE0004387, ucf:49400
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0004387

$Ultrafast Mechanisms of Nonlinear Refraction and Two-photon Photochromism$

Title: Ultrafast Mechanisms of Nonlinear Refraction and Two-photon Photochromism.
Creator: Zhao, Peng, Hagan, David, Vanstryland, Eric, Christodoulides, Demetrios, Hernandez, Florencio, University of Central Florida
Abstract / Description: Derived from a material's third-order nonlinearity, nonlinear refraction (NLR) occurs at any wavelength in any material, and may exhibit noninstantaneous dynamics depending on its physical origins. The main subject of this dissertation is to investigate the underlying mechanisms responsible for the NLR response in different phases of matter, e.g. liquids, gases, and semiconductors, by extensively using our recently developed ultrafast Beam Deflection (BD) technique. An additional subject...
Show moreDerived from a material's third-order nonlinearity, nonlinear refraction (NLR) occurs at any wavelength in any material, and may exhibit noninstantaneous dynamics depending on its physical origins. The main subject of this dissertation is to investigate the underlying mechanisms responsible for the NLR response in different phases of matter, e.g. liquids, gases, and semiconductors, by extensively using our recently developed ultrafast Beam Deflection (BD) technique. An additional subject includes the characterization of a novel two-photon photochromic molecule.In molecular liquids, the major nonlinear optical (NLO) response can be decomposed into a nearly instantaneous bound-electronic NLR (Kerr effect), originating from the real part the electronic second hyperpolarizability, ?, and noninstantaneous mechanisms due to nuclear motions. By adopting the methodology previously developed for carbon disulfide (CS2), we have measured the NLO response functions of 23 common organic solvents, providing a database of magnitudes and temporal dynamics of each mechanism, which can be used for predicting the outcomes of any other NLR related experiments such as Z-scan. Also, these results provide insight to relate solvent nonlinearities with their molecular structures as well as linear polarizability tensors. In the measurements of air and gaseous CS2, coherent Raman excitation of many rotational states manifests as revivals in the transient NLR, from which we identify N2, O2 and two isotopologues of CS2, and unambiguously determine the dephasing rate, and rotational and centrifugal constants of each constituent. Using the revival signal as a self-reference, ? is directly measured for CS2 molecules in gas phase, which coincides with the ? determined from liquid phase measurements when including the Lorentz-Lorenz local field correction. In semiconductors, the Kerr effect dominates the NLR in the sub-gap regime. Here, we primarily focus on investigating the dispersion of nondegenerate (ND) NLR, namely the refractive index change at frequency ?_a due to the presence of a beam at frequency ?_b. The magnitude and sign of the ND-NLR coefficient n_2 (?_a;?_b ) are determined for ZnO, ZnSe and CdS over a broad spectral range for different values of nondegeneracy, which closely follows our earlier predictions based on nonlinear Kramers-Kronig relations. In the extremely nondegenerate case, n_2 (?_a;?_b ) is positively enhanced near the two-photon absorption (2PA) edge, suggesting applications for nondegenerate all-optical switching. Additionally, n_2 (?_a;?_b ) exhibits a strong anomalous nonlinear dispersion within the ND-2PA spectral region, providing a large phase modulation of a femtosecond pulse with bandwidth centered near the zero-crossing frequency. Another subject of this dissertation is the characterization of a spiro-type two-photon photochromic molecule, in which F(&)#246;rster resonance energy transfer (FRET) is utilized to activate the ring-opening effect from a 2PA-donor chromophore. Evidence of energy transfer is observed via fluorescence measurements of the quantum yield, excitation spectra and anisotropy. The absorption and lifetime of the open form are measured in a dye-doped sol-gel matrix. Transient absorption measurements indicate both ring opening and closing occurs on a several picosecond time scale along with multiple transient photoproducts, from which a high FRET efficiency is measured in agreement with theoretical predictions. This efficient 2PA-FRET photochrome may be implemented into photonic devices such as optical memories. However, with a relatively small open-form absorption cross section and significant ring closing, the photochrome may not be viable for enhancing nonlinear absorption in applications such as optical limiting.
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Date Issued: 2016
Identifier: CFE0006517, ucf:51370
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006517

Title: OPTICAL SOLITONS IN PERIODIC STRUCTURES.
Creator: Makris, Konstantinos, Christodoulides, Demetrios, University of Central Florida
Abstract / Description: By nature discrete solitons represent self-trapped wavepackets in nonlinear periodic structures and result from the interplay between lattice diffraction (or dispersion) and material nonlinearity. In optics, this class of self-localized states has been successfully observed in both one-and two-dimensional nonlinear waveguide arrays. In recent years such lattice structures have been implemented or induced in a variety of material systems including those with cubic (Kerr), quadratic,...
Show moreBy nature discrete solitons represent self-trapped wavepackets in nonlinear periodic structures and result from the interplay between lattice diffraction (or dispersion) and material nonlinearity. In optics, this class of self-localized states has been successfully observed in both one-and two-dimensional nonlinear waveguide arrays. In recent years such lattice structures have been implemented or induced in a variety of material systems including those with cubic (Kerr), quadratic, photorefractive, and liquid-crystal nonlinearities. In all cases the underlying periodicity or discreteness leads to new families of optical solitons that have no counterpart whatsoever in continuous systems. In the first part of this dissertation, a theoretical investigation of linear and nonlinear optical wave propagation in semi-infinite waveguide arrays is presented. In particular, the properties and the stability of surface solitons at the edge of Kerr (AlGaAs) and quadratic (LiNbO3) lattices are examined. Hetero-structures of two dissimilar semi-infinite arrays are also considered. The existence of hybrid solitons in these latter types of structures is demonstrated. Rabi-type optical transitions in z-modulated waveguide arrays are theoretically demonstrated. The corresponding coupled mode equations, that govern the energy oscillations between two different transmission bands, are derived. The results are compared with direct beam propagation simulations and are found to be in excellent agreement with coupled mode theory formulations. In the second part of this thesis, the concept of parity-time-symmetry is introduced in the context of optics. More specifically, periodic potentials associated with PT-symmetric Hamiltonians are numerically explored. These new optical structures are found to exhibit surprising characteristics. These include the possibility of abrupt phase transitions, band merging, non-orthogonality, non-reciprocity, double refraction, secondary emissions, as well as power oscillations. Even though gain/loss is present in this class of periodic potentials, the propagation eigenvalues are entirely real. This is a direct outcome of the PT-symmetry. Finally, discrete solitons in PT-symmetric optical lattices are examined in detail.
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Date Issued: 2008
Identifier: CFE0002013, ucf:47610
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002013

Title: OPTICAL NONLINEAR INTERACTIONS IN DIELECTRIC NANO-SUSPENSIONS.
Creator: El-Ganainy, Ramy, Christodoulides, Demetrios, University of Central Florida
Abstract / Description: This work is divided into two main parts. In the first part (chapters 2-7) we consider the nonlinear response of nano-particle colloidal systems. Starting from the Nernst-Planck and Smoluchowski equations, we demonstrate that in these arrangements the underlying nonlinearities as well as the nonlinear Rayleigh losses depend exponentially on optical intensity. Two different nonlinear regimes are identified depending on the refractive index contrast of the nanoparticles involved and the...
Show moreThis work is divided into two main parts. In the first part (chapters 2-7) we consider the nonlinear response of nano-particle colloidal systems. Starting from the Nernst-Planck and Smoluchowski equations, we demonstrate that in these arrangements the underlying nonlinearities as well as the nonlinear Rayleigh losses depend exponentially on optical intensity. Two different nonlinear regimes are identified depending on the refractive index contrast of the nanoparticles involved and the interesting prospect of self-induced transparency is demonstrated. Soliton stability is systematically analyzed for both 1D and 2D configurations and their propagation dynamics in the presence of Rayleigh losses is examined. We also investigate the modulation instability of plane waves and the transverse instabilities of soliton stripe beams propagating in nonlinear nano-suspensions. We show that in these systems, the process of modulational instability depends on the boundary conditions. On the other hand, the transverse instability of soliton stripes can exhibit new features as a result of 1D collapse caused by the exponential nonlinearity. Many-body effects on the systems' nonlinear response are also examined. Mayer cluster expansions are used in order to investigate particle-particle interactions. We show that the optical nonlinearity of these nano-suspensions can range anywhere from exponential to polynomial depending on the initial concentration and the chemistry of the electrolyte solution. The consequence of these inter-particle interactions on the soliton dynamics and their stability properties are also studied. The second part deals with linear and nonlinear properties of optical nano-wires and the coupled mode formalism of parity-time (PT) symmetric waveguides. Dispersion properties of AlGaAs nano-wires are studied and it is shown that the group velocity dispersion in such waveguides can be negative, thus enabling temporal solitons. We have also studied power flow in nano-waveguides and we have shown that under certain conditions, optical pulses propagating in such structures will exhibit power circulations. Finally PT symmetric waveguides were investigated and a suitable coupled mode theory to describe these systems was developed.
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Date Issued: 2009
Identifier: CFE0002847, ucf:48538
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002847

Title: DISCRETE NONLINEAR WAVE PROPAGATION IN KERR NONLINEAR MEDIA.
Creator: Meier, Joachim, Stegeman, George, University of Central Florida
Abstract / Description: Discrete optical systems are a subgroup of periodic structures in which the evolution of a continuous electromagnetic field can be described by a discrete model. In this model, the total field is the sum of localized, discrete modes. Weakly coupled arrays of single mode channel waveguides have been known to fall into this class of systems since the late 1960's. Nonlinear discrete optics has received a considerable amount of interest in the last few years, triggered by the experimental...
Show moreDiscrete optical systems are a subgroup of periodic structures in which the evolution of a continuous electromagnetic field can be described by a discrete model. In this model, the total field is the sum of localized, discrete modes. Weakly coupled arrays of single mode channel waveguides have been known to fall into this class of systems since the late 1960's. Nonlinear discrete optics has received a considerable amount of interest in the last few years, triggered by the experimental realization of discrete solitons in a Kerr nonlinear AlGaAs waveguide array by H. Eisenberg and coworkers in 1998. In this work a detailed experimental investigation of discrete nonlinear wave propagation and the interactions between beams, including discrete solitons, in discrete systems is reported for the case of a strong Kerr nonlinearity. The possibility to completely overcome "discrete" diffraction and create highly localized solitons, in a scalar or vector geometry, as well as the limiting factors in the formation of such nonlinear waves is discussed. The reversal of the sign of diffraction over a range of propagation angles leads to the stability of plane waves in a material with positive nonlinearity. This behavior can not be found in continuous self-focusing materials where plane waves are unstable against perturbations. The stability of plane waves in the anomalous diffraction region, even at highest powers, has been experimentally verified. The interaction of high power beams and discrete solitons in arrays has been studied in detail. Of particular interest is the experimental verification of a theoretically predicted unique, all optical switching scheme, based on the interaction of a so called "blocker" soliton with a second beam. This switching method has been experimentally realized for both the coherent and incoherent case. Limitations of such schemes due to nonlinear losses at the required high powers are shown.
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Date Issued: 2004
Identifier: CFE0000186, ucf:46176
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000186

Title: Monolithically Integrated InP-based Unidirectional Circulators Utilizing non-Hermiticity and Nonlinearity.
Creator: Aleahmad, Parinaz, Christodoulides, Demetrios, Delfyett, Peter, Likamwa, Patrick, Moya Cessa, Hector Manual, University of Central Florida
Abstract / Description: The need to integrate critical optical components on a single chip has been an ongoing quest in both optoelectronics and optical communication systems. Among the possible devices, elements supporting non-reciprocal transmission are of great interest for applications where signal routing and isolation is required. In this respect, breaking reciprocity is typically accomplished via Faraday rotation through appropriate magneto-optical arrangements. Unfortunately, standard light emitting...
Show moreThe need to integrate critical optical components on a single chip has been an ongoing quest in both optoelectronics and optical communication systems. Among the possible devices, elements supporting non-reciprocal transmission are of great interest for applications where signal routing and isolation is required. In this respect, breaking reciprocity is typically accomplished via Faraday rotation through appropriate magneto-optical arrangements. Unfortunately, standard light emitting optoelectronic materials like for example III-V semiconductors, lack magneto-optical properties and hence cannot be directly used in this capacity. To address these issues, a number of different tactics have been attempted in the last few years. These range from directly bonding garnets on chip, to parametric structures and unidirectional nonlinear arrangements involving ring resonators, to mention a few. Clearly, of importance will be to realize families of non-reciprocal devises that not only can be miniaturized and readily integrated on chip but they also rely on physical processes that are indigenous to the semiconductor wafer itself. Quite recently we have theoretically shown that such unidirectional systems can be implemented, provided one simultaneously exploits the presence of gain/loss processes and optical nonlinearities. In principle, these all-dielectric structures can be broadband, polarization insensitive, color-preserving, and can display appreciable isolation ratios provided they are used under pulsed conditions. In this study, we experimentally demonstrate a compact, monolithically integrated unidirectional 4(&)#215;4 optical circulator, based on non-reciprocal optical transmission through successive amplification/attenuation stages and elements with very large resonance nonlinearities associated with InGaAsP quantum wells. Our results indicate that isolation ratios over 20dB can be experimentally achieved in pulse-mode operation. Our design can be effortlessly extended to other existing optoelectronic device systems beyond InP.
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Date Issued: 2016
Identifier: CFE0006522, ucf:51373
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006522

Title: NUMERICAL MODELING OF WAVE PROPAGATION IN NONLINEAR PHOTONIC CRYSTAL FIBER.
Creator: Khan, Md. Kaisar, Wu, Thomas, University of Central Florida
Abstract / Description: In this dissertation, we propose numerical techniques to explain physical phenomenon of nonlinear photonic crystal fiber (PCF). We explain novel physical effects occurred in PCF subjected to very short duration pulses including soliton. To overcome the limitations in the analytical formulation for PCF, an accurate and efficient numerical analysis is required to explain both linear and nonlinear physical characteristics. A vector finite element based model was developed to precisely synthesize...
Show moreIn this dissertation, we propose numerical techniques to explain physical phenomenon of nonlinear photonic crystal fiber (PCF). We explain novel physical effects occurred in PCF subjected to very short duration pulses including soliton. To overcome the limitations in the analytical formulation for PCF, an accurate and efficient numerical analysis is required to explain both linear and nonlinear physical characteristics. A vector finite element based model was developed to precisely synthesize the guided modes in order to evaluate coupling coefficients, nonlinear coefficient and higher order dispersions of PCFs. This finite element model (FEM) is capable of evaluating coupling length of directional coupler implemented in dual core PCF, which was supported by existing experimental results. We used the parameters extracted from FEM in higher order coupled nonlinear Schrödinger equation (HCNLSE) to model short duration pulses including soliton propagation through the PCF. Split-step Fourier Method (SSFM) was used to solve HCNLSE. Recently, reported experimental work reveals that the dual core PCF behaves like a nonlinear switch and also it initiates continuum generation which could be used as a broadband source for wavelength division multiplexing (WDM). These physical effects could not be explained by the existing analytical formulae such as the one used for the regular fiber. In PCF the electromagnetic wave encounters periodic changes of material that demand a numerical solution in both linear and nonlinear domain for better accuracy. Our numerical approach is capable of explaining switching and some of the spectral features found in the experiment with much higher degree of design freedom. Numerical results can also be used to further guide experiments and theoretical modeling.
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Date Issued: 2008
Identifier: CFE0002248, ucf:47879
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002248

Title: Coupling of Laser Beams for Filament Propagation.
Creator: Kepler, Daniel, Richardson, Martin, Baudelet, Matthieu, Christodoulides, Demetrios, University of Central Florida
Abstract / Description: Laser filamentation is a nonlinear process involving high-energy, ultrashort pulses that create narrow, non-diffracting structures over many times the Raleigh length. While many of the characteristics of filaments can vary greatly depending on the physical parameters used to create them, they share several defining features: a high intensity core, a lower intensity cladding of photons that serves as an energy reservoir to the core, and spectral broadening into a supercontinuum. While there...
Show moreLaser filamentation is a nonlinear process involving high-energy, ultrashort pulses that create narrow, non-diffracting structures over many times the Raleigh length. While many of the characteristics of filaments can vary greatly depending on the physical parameters used to create them, they share several defining features: a high intensity core, a lower intensity cladding of photons that serves as an energy reservoir to the core, and spectral broadening into a supercontinuum. While there have been many studies on the creation and control of multiple filaments from one laser pulse and a few studies on the interaction of two single filaments, many fundamental questions concerning the nature of this interaction still exist.This thesis seeks to explore the correlation between ultrashort pulses involving spatial separation, temporal delay, and relative degree of polarization using an interferometric approach. Evaluating the beam profiles and spectrum that result from varying those parameters.
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Date Issued: 2016
Identifier: CFE0006531, ucf:51374
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006531

Title: Nonlinear Optical Response of Simple Molecules and Two-Photon Semiconductor Lasers.
Creator: Reichert, Matthew, Vanstryland, Eric, Hagan, David, Likamwa, Patrick, Peale, Robert, University of Central Florida
Abstract / Description: This dissertation investigates two long standing issues in nonlinear optics: complete characterization of the ultrafast dynamics of simple molecules, and the potential of a two-photon laser using a bulk semiconductor gain medium. Within the Born-Oppenheimer approximation, nonlinear refraction in molecular liquids and gases can arise from both bound-electronic and nuclear origins. Knowledge of the magnitudes, temporal dynamics, polarization and spectral dependences of each of these mechanisms...
Show moreThis dissertation investigates two long standing issues in nonlinear optics: complete characterization of the ultrafast dynamics of simple molecules, and the potential of a two-photon laser using a bulk semiconductor gain medium. Within the Born-Oppenheimer approximation, nonlinear refraction in molecular liquids and gases can arise from both bound-electronic and nuclear origins. Knowledge of the magnitudes, temporal dynamics, polarization and spectral dependences of each of these mechanisms is important for many applications including filamentation, white-light continuum generation, all-optical switching, and nonlinear spectroscopy. In this work the nonlinear dynamics of molecules are investigated in both liquid and gas phase with the recently developed beam deflection technique which measures nonlinear refraction directly in the time domain. Thanks to the utility of the beam deflection technique we are able to completely determine the third-order response function of one of the most important molecular liquids in nonlinear optics, carbon disulfide. This allows the prediction of essentially any nonlinear refraction or two-photon absorption experiment on CS2. Measurements conducted on air (N2 and O2) and gaseous CS2 reveal coherent rotational revivals in the degree of alignment of the ensemble at a period that depends on its moment of inertia. This allows measurement of the rotational and centrifugal distortion constants of the isolated molecules. Additionally, the rotational contribution to the beam deflection measurement can be eliminated thanks to the particular polarization dependence of the mechanism. At a specific polarization, the dominant remaining contribution is due to the bound-electrons. Thus both the bound-electronic nonlinear refractive index of air, and second hyperpolarizability of isolated CS2 molecules, are measured directly. The later agrees well with liquid CS2 measurements, where local field effects are significant. The second major portion of this dissertation addresses the possibility of using bulk semiconductors as a two-photon gain medium. A two-photon laser has been a goal of nonlinear optics since shortly after the original laser's development. In this case, two-photons are emitted from a single electronic transition rather than only one. This processes is known as two-photon gain (2PG). Semiconductors have large two-photon absorption coefficients, which are enhanced by ~2 orders of magnitude when using photons of very different energies, e.g., ??_a?10??_b. This enhancement should translate into large 2PG coefficients as well, given the inverse relationship between absorption and gain. Here, we experimentally demonstrate both degenerate and nondegenerate 2PG in optically excited bulk GaAs via pump-probe experiments. This constitutes, to my knowledge, the first report of nondegenerate two-photon gain. Competition between 2PG and competing processes, namely intervalence band and nondegenerate three-photon absorption (ND-3PA), in both cases are theoretically analyzed. Experimental measurements of ND-3PA agree with this analysis and show that it is enhanced much more than ND-2PG. It is found for both degenerate and nondegenerate photon pairs that the losses dominate the two-photon gain, preventing the possibility of a two-photon semiconductor laser.
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Date Issued: 2015
Identifier: CFE0005874, ucf:50871
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005874

Title: QUADRATIC SPATIAL SOLITON INTERACTIONS.
Creator: Jankovic, Ladislav, Stegeman, George I., University of Central Florida
Abstract / Description: Quadratic spatial soliton interactions were investigated in this Dissertation. The first part deals with characterizing the principal features of multi-soliton generation and soliton self-reflection. The second deals with two beam processes leading to soliton interactions and collisions. These subjects were investigated both theoretically and experimentally. The experiments were performed by using potassium niobate (KNBO3) and periodically poled potassium titanyl phosphate (KTP) crystals....
Show moreQuadratic spatial soliton interactions were investigated in this Dissertation. The first part deals with characterizing the principal features of multi-soliton generation and soliton self-reflection. The second deals with two beam processes leading to soliton interactions and collisions. These subjects were investigated both theoretically and experimentally. The experiments were performed by using potassium niobate (KNBO3) and periodically poled potassium titanyl phosphate (KTP) crystals. These particular crystals were desirable for these experiments because of their large nonlinear coefficients and, more importantly, because the experiments could be performed under non-critical-phase-matching (NCPM) conditions. The single soliton generation measurements, performed on KNBO3 by launching the fundamental component only, showed a broad angular acceptance bandwidth which was important for the soliton collisions performed later. Furthermore, at high input intensities multi-soliton generation was observed for the first time. The influence on the multi-soliton patterns generated of the input intensity and beam symmetry was investigated. The combined experimental and theoretical efforts indicated that spatial and temporal noise on the input laser beam induced multi-soliton patterns. Another research direction pursued was intensity dependent soliton routing by using of a specially engineered quadratically nonlinear interface within a periodically poled KTP sample. This was the first time demonstration of the self-reflection phenomenon in a system with a quadratic nonlinearity. The feature investigated is believed to have a great potential for soliton routing and manipulation by engineered structures. A detailed investigation was conducted on two soliton interaction and collision processes. Birth of an additional soliton resulting from a two soliton collision was observed and characterized for the special case of a non-planar geometry. A small amount of spiraling, up to 30 degrees rotation, was measured in the experiments performed. The parameters relevant for characterizing soliton collision processes were also studied in detail. Measurements were performed for various collision angles (from 0.2 to 4 degrees), phase mismatch, relative phase between the solitons and the distance to the collision point within the sample (which affects soliton formation). Both the individual and combined effects of these collision variables were investigated. Based on the research conducted, several all-optical switching scenarios were proposed.
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Date Issued: 2004
Identifier: CFE0000090, ucf:46135
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000090

Title: Techniques for characterization of third order optical nonlinearities.
Creator: Ferdinandus, Manuel, Hagan, David, Vanstryland, Eric, Christodoulides, Demetrios, Hernandez, Florencio, University of Central Florida
Abstract / Description: This dissertation describes the development of novel techniques for characterization of nonlinear properties of materials. The dissertation is divided into two parts, a background and theory section and a technique development section.In the background and theory section we explain the origins of the nonlinear optical response of materials across many different spatial and temporal scales. The mechanisms that we are most interested in are the electronic nuclear and reorientational responses,...
Show moreThis dissertation describes the development of novel techniques for characterization of nonlinear properties of materials. The dissertation is divided into two parts, a background and theory section and a technique development section.In the background and theory section we explain the origins of the nonlinear optical response of materials across many different spatial and temporal scales. The mechanisms that we are most interested in are the electronic nuclear and reorientational responses, which occur on the range of sub-femtosecond to several picoseconds. The electronic mechanism is due to the electrons of a material experiencing a non-parabolic potential well due a strong electric field and occurs on the sub-femtosecond timescale. The nuclear or vibrational effect results from the motion of the nuclei of the atoms and typically occurs on the order of a few hundred femtoseconds. Finally the reorientational nonlinearity is due to the alignment of the molecule to the electric field, which alters the polarizability of the molecule and typically occurs on the scale of a few picoseconds. There are other mechanisms can induce nonlinear optical effects such as thermal effects and electrostriction, but these effects typically occur on much larger timescales than we are interested in, and hence will not be a major focus of this dissertation.In the nonlinear characterization techniques section, we describe previous research into the field of nonlinear optical characterization techniques, describing the techniques used to characterize the nonlinear properties of materials, their applications and limitations. We will trace the development of two recently developed techniques for nonlinear spectroscopy ? the Dual Arm Z-Scan and the Beam Deflection techniques. The Dual Arm Z-Scan technique is an enhancement of the standard Z-Scan technique that allows for the measurement of small nonlinear signals in the presence of large background signals. This technique allows for the measurement of materials under certain conditions not previously measureable using the standard Z-Scan technique, such materials with low damage thresholds, poor solubility and thin films.In addition to the Dual Arm Z-Scan, we have developed a new method for characterizing nonlinear refraction, the Beam Deflection technique, which is a variation of the photothermal beam deflection technique previously used to measure very weak absorption signals. This technique offers relative ease of use, the ability to measure the absolute magnitude and sign of both the real and imaginary parts of ?^((3)) simultaneously with high sensitivity. We fully develop the theory for materials with instantaneous and non-instantaneous nonlinearities, with nonlinear absorption and group velocity mismatch. We also demonstrate the power of this technique to separate the isotropic and reorientational contributions of liquids by examining the temporal response and polarization dependences.Lastly, we summarize our conclusions and describe two promising future research directions that would benefit from the Dual Arm Z-Scan and Beam Deflection techniques.
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Date Issued: 2013
Identifier: CFE0005164, ucf:50709
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005164

Title: LASER FILAMENT INTERACTION WITH AEROSOLS AND CLOUDS.
Creator: Jeon, Cheonha, Richardson, Martin, Vanstryland, Eric, Baudelet, Matthieu, Sigman, Michael, University of Central Florida
Abstract / Description: A high powered ultrashort laser pulse can propagate as a diffraction-free self-channeled structure called a filament, created by a combination of nonlinear processes. With its ability to convey extremely high intensity beams to distant targets, many applications such as remote sensing, cloud seeding, and discharge guiding are potentially possible. However, one of the main challenges of outdoor field applications is the laser propagation through the atmosphere where pressure fluctuations and...
Show moreA high powered ultrashort laser pulse can propagate as a diffraction-free self-channeled structure called a filament, created by a combination of nonlinear processes. With its ability to convey extremely high intensity beams to distant targets, many applications such as remote sensing, cloud seeding, and discharge guiding are potentially possible. However, one of the main challenges of outdoor field applications is the laser propagation through the atmosphere where pressure fluctuations and concentrations of aerosols may be present. The rationale behind the work presented in this dissertation is to evaluate the robustness of the filamentation, measure the interaction losses as well as understanding the modifications to (i) filament length (ii) supercontinuum generation, and (iii) the beam profile along propagation through perturbed media.Detailed studies of the interaction of a single filament with a single water droplet are presented. In addition, preliminary results on filament propagation through a cloud of aerosols are discussed. The effect of pressure on the beam profile along propagation and on the supercontinuum generated by the filament is studied. This document provides valuable insight into the complex nonlinear processes affecting the formation, propagation and post propagation of filaments under adverse atmospheric conditions.
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Date Issued: 2016
Identifier: CFE0006530, ucf:51368
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006530

Title: Cascaded plasmon resonances for enhanced nonlinear optical response.
Creator: Toroghi, Seyfollah, Kik, Pieter, Vanstryland, Eric, Kuebler, Stephen, Hagan, David, Belfield, Kevin, University of Central Florida
Abstract / Description: The continued development of integrated photonic devices requires low-power, small volume all-optical modulators. The weak nonlinear optical response of conventional optical materials requires the use of high intensities and large interaction volumes in order to achieve significant light modulation, hindering the miniaturization of all-optical switches and the development of lightweight transmission optics with nonlinear optical response. These challenges may be addressed using plasmonic...
Show moreThe continued development of integrated photonic devices requires low-power, small volume all-optical modulators. The weak nonlinear optical response of conventional optical materials requires the use of high intensities and large interaction volumes in order to achieve significant light modulation, hindering the miniaturization of all-optical switches and the development of lightweight transmission optics with nonlinear optical response. These challenges may be addressed using plasmonic nanostructures due to their unique ability to confine and enhance electric fields in sub-wavelength volumes. The ultrafast nonlinear response of free electrons in such plasmonic structures and the fast thermal nonlinear optical response of metal nanoparticles, as well as the plasmon enhanced nonlinear Kerr-type response of the host material surrounding the nanostructures could allow ultrafast all-optical modulation with low modulation energy. In this thesis, we investigate the linear and nonlinear optical response of engineered effective media containing coupled metallic nanoparticles. The fundamental interactions in systems containing coupled nanoparticles with size, shape, and composition dissimilarity, are evaluated analytically and numerically, and it is demonstrated that under certain conditions the achieved field enhancement factors can exceed the single-particle result by orders of magnitude in a process called cascaded plasmon resonance. It is demonstrated that these conditions can be met in systems containing coupled nanospheres, and in systems containing non-spherical metal nanoparticles that are compatible with common top-down nanofabrication methods such as electron beam lithography and nano-imprint lithography. We show that metamaterials based on such cascaded plasmon resonance structures can produce enhanced nonlinear optical refraction and absorption compared to that of conventional plasmonic nanostructures. Finally, it is demonstrated that the thermal nonlinear optical response of metal nanoparticles can be enhanced in carefully engineered heterogeneous nanoparticle clusters, potentially enabling strong and fast thermal nonlinear optical response in system that can be produced in bulk through chemical synthesis.
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Date Issued: 2014
Identifier: CFE0005556, ucf:50272
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005556

Title: Nonlinear integrated photonics on silicon and gallium arsenide substrates.
Creator: Ma, Jichi, Fathpour, Sasan, Hagan, David, Li, Guifang, Peale, Robert, University of Central Florida
Abstract / Description: Silicon photonics is nowadays a mature technology and is on the verge of becoming a blossoming industry. Silicon photonics has also been pursued as a platform for integrated nonlinear optics based on Raman and Kerr effects. In recent years, more futuristic directions have been pursued by various groups. For instance, the realm of silicon photonics has been expanded beyond the well-established near-infrared wavelengths and into the mid-infrared (3 (-) 5 (&)#181;m). In this wavelength range,...
Show moreSilicon photonics is nowadays a mature technology and is on the verge of becoming a blossoming industry. Silicon photonics has also been pursued as a platform for integrated nonlinear optics based on Raman and Kerr effects. In recent years, more futuristic directions have been pursued by various groups. For instance, the realm of silicon photonics has been expanded beyond the well-established near-infrared wavelengths and into the mid-infrared (3 (-) 5 (&)#181;m). In this wavelength range, the omnipresent hurdle of nonlinear silicon photonics in the telecommunication band, i.e., nonlinear losses due to two-photon absorption, is inherently nonexistent. With the lack of efficient light-emission capability and second-order optical nonlinearity in silicon, heterogeneous integration with other material systems has been another direction pursued. Finally, several approaches have been proposed and demonstrated to address the energy efficiency of silicon photonic devices in the near-infrared wavelength range. In this dissertation, theoretical and experimental works are conducted to extend applications of integrated photonics into mid-infrared wavelengths based on silicon, demonstrate heterogeneous integration of tantalum pentoxide and lithium niobate photonics on silicon substrates, and study two-photon photovoltaic effect in gallium arsenide and plasmonic-enhanced structures.Specifically, performance and noise properties of nonlinear silicon photonic devices, such as Raman lasers and optical parametric amplifiers, based on novel and reliable waveguide technologies are studied. Both near-infrared and mid-infrared nonlinear silicon devices have been studied for comparison. Novel tantalum-pentoxide- and lithium-niobate-on-silicon platforms are developed for compact microring resonators and Mach-Zehnder modulators. Third- and second-harmonic generations are theoretical studied based on these two platforms, respectively. Also, the two-photon photovoltaic effect is studied in gallium arsenide waveguides for the first time. The effect, which was first demonstrated in silicon, is the nonlinear equivalent of the photovoltaic effect of solar cells and offers a viable solution for achieving energy-efficient photonic devices. The measured power efficiency achieved in gallium arsenide is higher than that in silicon and even higher efficiency is theoretically predicted with optimized designs. Finally, plasmonic-enhanced photovoltaic power converters, based on the two-photon photovoltaic effect in silicon using subwavelength apertures in metallic films, are proposed and theoretically studied.
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Date Issued: 2014
Identifier: CFE0005373, ucf:50441
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0005373

Title: STUDY OF THE EXCITED-STATE ABSORPTION PROPERTIES OF POLYMETHINE MOLECULES.
Creator: Lepkowicz, Richard Stanley, Van Stryland, Eric W., University of Central Florida
Abstract / Description: This dissertation investigates excited-state nonlinearities in a series of polymethine dyes for the application of nanosecond optical limiting. Optical limiters are devices that for low intensity light exhibit a high linear transmittance, but for high intensity light strongly attenuate the incident radiation. These devices would serve to protect optical sensors from intense laser radiation by clamping the maximum energy allowed through an optical system below the damage threshold of the...
Show moreThis dissertation investigates excited-state nonlinearities in a series of polymethine dyes for the application of nanosecond optical limiting. Optical limiters are devices that for low intensity light exhibit a high linear transmittance, but for high intensity light strongly attenuate the incident radiation. These devices would serve to protect optical sensors from intense laser radiation by clamping the maximum energy allowed through an optical system below the damage threshold of the sensor. The search is ongoing for optical materials that are both broadband and have high damage thresholds to be effective materials for limiting applications. Polymethine dyes are promising compounds due to a strong and broad excited-state absorption (ESA) band in the visible region. However, the effectiveness of polymethine molecules as applied to optical limiting is hindered by a saturation of the ESA process at high fluences. Experiments and theoretical modeling are performed to determine the root causes of this saturation effect in both the picosecond and nanosecond time regime. The polymethine molecules studied have chromophore lengths from di- to pentacarbocyanine (2 to 5 -CH=CH- groups) with various bridge structures. This allows us to develop relationships between the molecular parameters of the polymethine molecules and overall nonlinear absorption performance. The experiments conducted included femtosecond white light continuum pump-probe experiments to measure ESA spectra, picosecond two-color polarization-resolved pump-probe to measure excited-state dynamics and the orientation of transition dipole moments, and picosecond and nanosecond optical limiting and z-scans. From these experiments we are able to develop energy level models that describe the nonlinear absorption processes in polymethines from the picosecond to nanosecond time regime. This work, along with the quantum chemical modeling performed at the Institute of Physics and National Academy of Sciences of Ukraine, has resulted in the creation of dyes that have improved photochemical stability with larger nonlinearities. These are useful not only for optical limiting but also for a wide variety of nonlinear optical applications.
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Date Issued: 2004
Identifier: CFE0000002, ucf:46115
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000002

Title: OPTICAL WAVE PROPAGATION IN DISCRETE WAVEGUIDE ARRAYS.
Creator: Hudock, Jared, Christodoulides, Demetrios, University of Central Florida
Abstract / Description: The propagation dynamics of light in optical waveguide arrays is characteristic of that encountered in discrete systems. As a result, it is possible to engineer the diffraction properties of such structures, which leads to the ability to control the flow of light in ways that are impossible in continuous media. In this work, a detailed theoretical investigation of both linear and nonlinear optical wave propagation in one- and two-dimensional waveguide lattices is presented. The ability to...
Show moreThe propagation dynamics of light in optical waveguide arrays is characteristic of that encountered in discrete systems. As a result, it is possible to engineer the diffraction properties of such structures, which leads to the ability to control the flow of light in ways that are impossible in continuous media. In this work, a detailed theoretical investigation of both linear and nonlinear optical wave propagation in one- and two-dimensional waveguide lattices is presented. The ability to completely overcome the effects of discrete diffraction through the mutual trapping of two orthogonally polarized coherent beams interacting in Kerr nonlinear arrays of birefringent waveguides is discussed. The existence and stability of such highly localized vector discrete solitons is analyzed and compared to similar scenarios in a single birefringent waveguide. This mutual trapping is also shown to occur within the first few waveguides of a semi-infinite array leading to the existence of vector discrete surface waves. Interfaces between two detuned semi-infinite waveguide arrays or waveguide array heterojunctions and their possible applications are also considered. It is shown that the detuning between the two arrays shifts the dispersion relation of one array with respect to the other. Consequently, these systems provide spatial filtering functions that may prove useful in future all-optical networks. In addition by exploiting the unique diffraction properties of discrete arrays, diffraction compensation can be achieved in a way analogous to dispersion compensation in dispersion managed optical fiber systems. Finally, it is demonstrated that both the linear (diffraction) and nonlinear dynamics of two-dimensional waveguide arrays are significantly more complex and considerably more versatile than their one-dimensional counterparts. As is the case in one-dimensional arrays, the discrete diffraction properties of these two-dimensional lattices can be effectively altered depending on the propagation Bloch k-vector within the first Brillouin zone. In general, this diffraction behavior is anisotropic and as a result, allows the existence of a new class of discrete elliptic solitons in the nonlinear regime. Moreover, such arrays support two-dimensional vector soliton states, and their existence and stability are also thoroughly explored in this work.
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Date Issued: 2005
Identifier: CFE0000833, ucf:46687
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0000833

Title: FEMTOSECOND LASER WRITTEN VOLUMETRIC DIFFRACTIVE OPTICAL ELEMENTS AND THEIR APPLICATIONS.
Creator: Choi, Jiyeon, Richardson, Martin, University of Central Florida
Abstract / Description: Since the first demonstration of femtosecond laser written waveguides in 1996, femtosecond laser direct writing (FLDW) has been providing a versatile means to fabricate embedded 3-D microstructures in transparent materials. The key mechanisms are nonlinear absorption processes that occur when a laser beam is tightly focused into a material and the intensity of the focused beam reaches the range creating enough free electrons to induce structural modification. One of the most useful features...
Show moreSince the first demonstration of femtosecond laser written waveguides in 1996, femtosecond laser direct writing (FLDW) has been providing a versatile means to fabricate embedded 3-D microstructures in transparent materials. The key mechanisms are nonlinear absorption processes that occur when a laser beam is tightly focused into a material and the intensity of the focused beam reaches the range creating enough free electrons to induce structural modification. One of the most useful features that can be exploited in fabricating photonic structures is the refractive index change which results from the localized energy deposition. The laser processing system for FLDW can be realized as a compact, desktop station, implemented by a laser source, a 3-D stage and focusing optics. Thus, FLDW can be readily adopted for the fabrication of the photonic devices. For instance, it has been widely employed in various areas of photonic device fabrication such as active and passive waveguides, couplers, gratings, opto-fluidics and similar applications. This dissertation describes the use of FLDW towards the fabrication of custom designed diffractive optical elements (DOE's). These are important micro-optical elements that are building blocks in integrated optical devices including on-chip sensors and systems. The fabrication and characterization of laser direct written DOEs in different glass materials is investigated. The design and performance of a range of DOE's is described, especially, laser-written embedded Fresnel zone plates and linear gratings. Their diffractive efficiency as a function of the fabrication parameters is discussed and an optimized fabrication process is realized. The potential of the micro-DOEs and their integration shown in this dissertation will impact on the fabrication of future on-chip devices involving customized DOEs that will serve great flexibility and multi-functional capability on sensing, imaging and beam shaping.
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Date Issued: 2009
Identifier: CFE0002958, ucf:47984
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0002958

Title: Thin-film Lithium Niobate Photonics for Electro-optics, Nonlinear Optics, and Quantum Optics on Silicon.
Creator: Rao, Ashutosh, Fathpour, Sasan, Delfyett, Peter, Li, Guifang, Thomas, Jayan, University of Central Florida
Abstract / Description: Ion-sliced thin-film lithium niobate (LN) compact waveguide technology has facilitated the resurgence of integrated photonics based on lithium niobate. These thin-film LN waveguides offer over an order of magnitude improvement in optical confinement, and about two orders of magnitude reduction in waveguide bending radius, compared to conventional LN waveguides. Harnessing the improved confinement, a variety of miniaturized and efficient photonic devices are demonstrated in this work. First,...
Show moreIon-sliced thin-film lithium niobate (LN) compact waveguide technology has facilitated the resurgence of integrated photonics based on lithium niobate. These thin-film LN waveguides offer over an order of magnitude improvement in optical confinement, and about two orders of magnitude reduction in waveguide bending radius, compared to conventional LN waveguides. Harnessing the improved confinement, a variety of miniaturized and efficient photonic devices are demonstrated in this work. First, two types of compact electrooptic modulators are presented (-) microring modulators, and Mach-Zehnder modulators. Next, two distinct approaches to nonlinear optical frequency converters are implemented (-) periodically poled lithium niobate, and mode shape modulation (grating assisted quasi-phase matching). Following this, stochastic variations are added to the mode shape modulation approach to demonstrate random quasi-phase matching. Afterward, broadband photon-pair generation is demonstrated in the miniaturized periodically poled lithium niobate, and spectral correlations of the biphoton spectrum are reported. Finally, extensions of the aforementioned results suitable for future work are discussed.
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Date Issued: 2018
Identifier: CFE0007085, ucf:52013
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007085

Title: MOLECULAR STRUCTURE – NONLINEAR OPTICAL PROPERTY RELATIONSHIPS FOR A SERIES OF POLYMETHINE AND SQUARAINE MOLECULES.
Creator: Fu, Jie, Van Stryland, Eric, University of Central Florida
Abstract / Description: This dissertation reports on the investigation of the relationships between molecular structure and two-photon absorption (2PA) properties for a series of polymethine and squaraine molecules. Current and emerging applications exploiting the quadratic dependence upon laser intensity, such as two-photon fluorescence imaging, three-dimensional microfabrication, optical data storage and optical limiting, have motivated researchers to find novel materials exhibiting strong 2PA. Organic materials...
Show moreThis dissertation reports on the investigation of the relationships between molecular structure and two-photon absorption (2PA) properties for a series of polymethine and squaraine molecules. Current and emerging applications exploiting the quadratic dependence upon laser intensity, such as two-photon fluorescence imaging, three-dimensional microfabrication, optical data storage and optical limiting, have motivated researchers to find novel materials exhibiting strong 2PA. Organic materials are promising candidates because their linear and nonlinear optical properties can be optimized for applications by changing their structures through molecular engineering. Polymethine and squaraine dyes are particularly interesting because they are fluorescent and showing large 2PA. We used three independent nonlinear spectroscopic techniques (Z-scan, two-photon fluorescence and white-light continuum pump-probe spectroscopy) to obtain the 2PA spectra revealing 2PA bands, and we confirm the experimental data by comparing the results from the different methods mentioned. By systematically altering the structure of polyemthines and squaraines, we studied the effects of molecular symmetry, strength of donor terminal groups, conjugation length of the chromophore chain, polarity of solvents, and the effects of placing bridge molecules inside the chromophore chain on the 2PA properties. We also compared polymethine, squaraine, croconium and tetraon dyes with the same terminal groups to study the effects of the different additions inserted within the chromophore chain on their optical properties. Near IR absorbing squaraine dyes were experimentally observed to show extremely large 2PA cross sections ( 30000GM). A simplified three-level model was used to fit the measured 2PA spectra and detailed quantum chemical calculations revealed the reasons for the squaraine to exhibit strong 2PA. In addition, two-photon excitation fluorescence anisotropy spectra were measured through multiple 2PA transitions. A theoretical model based on four-levels with two intermediate states was derived and used for analysis of the experimental data.
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Date Issued: 2006
Identifier: CFE0001350, ucf:46967
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0001350

nonlinear optics (13)	+ -
Nonlinear Optics (8)	+ -
Nonlinear optics (4)	+ -
integrated photonics (4)	+ -
Two-Photon Absorption (3)	+ -

Filamentation (2)	+ -
Solitons (2)	+ -
nonlinear guided waves (2)	+ -
second harmonic generation (2)	+ -
silicon photonics (2)	+ -
solitons (2)	+ -
1PA (1)	+ -
2PA (1)	+ -
Anisotropy (1)	+ -
Axicon (1)	+ -
Bessel Beams (1)	+ -
Cascaded Field Enhancement (1)	+ -
Chrage Transport (1)	+ -
Coherent transients (1)	+ -
Computational Chemistry (1)	+ -
Conjugated Chromophore (1)	+ -
DFT (1)	+ -
Diffraction (1)	+ -
Discrete Optics (1)	+ -
Energy Projection (1)	+ -
Exchange-Correlation Functionals. (1)	+ -
Excited State Dynamics (1)	+ -
Excitons (1)	+ -
FEM and Nonlinear Optics (1)	+ -
Femtosecond (1)	+ -

University of Central Florida (35)	+ -
Christodoulides, Demetrios (12)	+ -
Hagan, David (10)	+ -
Vanstryland, Eric (9)	+ -
Richardson, Martin (7)	+ -

Likamwa, Patrick (5)	+ -
Delfyett, Peter (4)	+ -
Fathpour, Sasan (4)	+ -
Peale, Robert (4)	+ -
Amezcua Correa, Rodrigo (3)	+ -
Hernandez, Florencio (3)	+ -
Baudelet, Matthieu (2)	+ -
Kik, Pieter (2)	+ -
Li, Guifang (2)	+ -
Masunov, Artem (2)	+ -
Thomas, Jayan (2)	+ -
Van Stryland, Eric (2)	+ -
Van Stryland, Eric W. (2)	+ -
Zeldovich, Boris (2)	+ -
Aleahmad, Parinaz (1)	+ -
Balaeff, Alexander (1)	+ -
Barbieri, Nicholas (1)	+ -
Belfield, Kevin (1)	+ -
Camacho Gonzalez, Guillermo Fernando (1)	+ -
Chanda, Debashis (1)	+ -
Chang, Zenghu (1)	+ -
Chantharasupawong, Panit (1)	+ -
Chen, Zhigang (1)	+ -
Choi, Jiyeon (1)	+ -
Cirloganu, Claudiu (1)	+ -

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