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NEW ORGANIC/INORGANIC HYBRID SOL-GEL NANOCOMPOSITE MATERIALS FOR RAMAN GAIN IN FIBER OPTICS
Title
NEW ORGANIC/INORGANIC HYBRID SOL-GEL NANOCOMPOSITE MATERIALS FOR RAMAN GAIN IN FIBER OPTICS.
Creator
Andrasik, Stephen James, Belfield, Kevin D., University of Central Florida
Abstract / Description
ABSTRACTThe recent increased availability of additional wavelengths in the telecommunications window of about 1300-1600 nm has generated an interest in new optical materials and devices that can operate outside the normally used regions of 840 nm, 1310 nm, and 1550 nm. Specifically, methods to amplify fiber optical data transmission in the regions where there is limited or no existing methods to achieve amplification is of interest in the chemistry and photonic communities. Raman gain is one...
Show moreABSTRACTThe recent increased availability of additional wavelengths in the telecommunications window of about 1300-1600 nm has generated an interest in new optical materials and devices that can operate outside the normally used regions of 840 nm, 1310 nm, and 1550 nm. Specifically, methods to amplify fiber optical data transmission in the regions where there is limited or no existing methods to achieve amplification is of interest in the chemistry and photonic communities. Raman gain is one method that has been proposed to passively amplify optical data transmission through a distributed process. Amplification is obtained through a nonlinear light scattering process where an optical wave is amplified at the expense of a higher frequency pump wave. Multiple wavelengths can be evenly amplified simultaneously in a desired region by specific selection of one or more pump wavelengths. Herein, the synthesis and characterization of new hybrid inorganic/organic sol-gels and monomers capable of producing broad wavelength Raman scattering over a spectral range of 1200-1670 nm are presented. The synthetic methodology developed facilitates the systematic approach to produce sol-gel derivatives with functional groups known to be strongly Raman scattering. Additionally, a method to synthesize and characterize a large number of different compounds using a combinatorial approach was demonstrated. Thio based derivatives of sulfonyldiphenol, isopropylidenediphenol, and triallyloxy triazine were synthesized in addition to thio derivatives of poly(hydroxystyrene). Micro-Raman spectra of the hybrid sol-gels, thio-based derivatives, and IR spectra of select sol-gel monomers were obtained.
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Date Issued
2004
Identifier
CFE0000028, ucf:46094
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0000028
SINGLET OXYGEN GENERATION USING NEW FLUORENE-BASED PHOTOSENSITIZERS UNDER ONE- AND TWO-PHOTON EXCITATION
Title
SINGLET OXYGEN GENERATION USING NEW FLUORENE-BASED PHOTOSENSITIZERS UNDER ONE- AND TWO-PHOTON EXCITATION.
Creator
Andrasik, Stephen, Belfield, Kevin, University of Central Florida
Abstract / Description
Molecular oxygen in its lowest electronically excited state plays an important roll in the field of chemistry. This excited state is often referred to as singlet oxygen and can be generated in a photosensitized process under one- or two-photon excitation of a photosensitizer. It is particularly useful in the field of photodynamic cancer therapy (PDT) where singlet oxygen formation can be used to destroy cancerous tumors. The use of two-photon activated photosensitizers possesses great...
Show moreMolecular oxygen in its lowest electronically excited state plays an important roll in the field of chemistry. This excited state is often referred to as singlet oxygen and can be generated in a photosensitized process under one- or two-photon excitation of a photosensitizer. It is particularly useful in the field of photodynamic cancer therapy (PDT) where singlet oxygen formation can be used to destroy cancerous tumors. The use of two-photon activated photosensitizers possesses great potential in the field of PDT since near-IR light is used to activate the sensitizer, resulting in deeper penetration of light into biological tissue, less photo-bleaching of the sensitizer, and greatly improved resolution of excitation. The synthesis and photophysical characterization of new fluorene-based photosensitizers for efficient singlet oxygen production were investigated. The spectral properties for singlet oxygen production were measured at room temperature and 77 K. Two-photon absorption (2PA) cross-sections of the fluorene derivatives were measured by the open aperture Z-scan method. The quantum yields of singlet oxygen generation under one- and two-photon excitation (ΦΔ and 2PAΦΔ, respectively) were determined by the direct measurement of singlet oxygen luminescence at ≈ 1270 nm. The values of ΦΔ were independent of excitation wavelength, ranging from 0.6 - 0.9. The singlet oxygen quantum yields under two-photon excitation were 2PAΦΔ ≈ ½ΦΔ, indicating that the two processes exhibited the same mechanism of singlet oxygen production, independent of the mechanism of photon absorption.
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Date Issued
2007
Identifier
CFE0001860, ucf:47411
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0001860