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CHARACTERIZATION OF THE NONLINEAR REFRACTIVE INDEX OF CARBONDISULFIDE OVER AN EXTENDED SPECTRAL AND TEMPORAL RANGE

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Date Issued:
2011
Abstract/Description:
The intensity dependent refractive index change of a medium is frequently described in terms of the product n2xI where n2 is the nonlinear refractive index and I the light intensity. The nonlinear refractive index is often treated as constant which is a reasonable assumption if the light interacts only with bound electrons. In the case of carbon disulfide (CS2) however, nuclear motions contribute to n2. These motions occur on the sub picosecond time scale and thus become especially relevant for ultrashort laser pulses. The neat liquid CS2 is studied because it exhibits a large nonlinear refractive index in comparison to other liquids. Therefore, it is employed in optical switching, optical limiting, and beam filamentation applications. This thesis presents effective n2 values for Gaussian shaped linearly polarized pulses with central wavelengths of 700nm. A theoretical model describing the time evolution of the material response is applied to distinguish between the instantaneous electronic, the ultrafast nuclear and the slow nuclear origins of the nonlinear refractive index. Moreover, the tensor nature of the material response function is studied by means of circularly polarized light. The relative magnitudes of bound electronic and nuclear contributions to n2 are experimentally determined. Eventually, the dispersion of the instantaneous electronic response is measured in the spectral range between 411nm and 1064nm.
Title: CHARACTERIZATION OF THE NONLINEAR REFRACTIVE INDEX OF CARBONDISULFIDE OVER AN EXTENDED SPECTRAL AND TEMPORAL RANGE.
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Name(s): Seidel, Marcus, Author
Van Stryland, Eric, Committee Chair
University of Central Florida, Degree Grantor
Type of Resource: text
Date Issued: 2011
Publisher: University of Central Florida
Language(s): English
Abstract/Description: The intensity dependent refractive index change of a medium is frequently described in terms of the product n2xI where n2 is the nonlinear refractive index and I the light intensity. The nonlinear refractive index is often treated as constant which is a reasonable assumption if the light interacts only with bound electrons. In the case of carbon disulfide (CS2) however, nuclear motions contribute to n2. These motions occur on the sub picosecond time scale and thus become especially relevant for ultrashort laser pulses. The neat liquid CS2 is studied because it exhibits a large nonlinear refractive index in comparison to other liquids. Therefore, it is employed in optical switching, optical limiting, and beam filamentation applications. This thesis presents effective n2 values for Gaussian shaped linearly polarized pulses with central wavelengths of 700nm. A theoretical model describing the time evolution of the material response is applied to distinguish between the instantaneous electronic, the ultrafast nuclear and the slow nuclear origins of the nonlinear refractive index. Moreover, the tensor nature of the material response function is studied by means of circularly polarized light. The relative magnitudes of bound electronic and nuclear contributions to n2 are experimentally determined. Eventually, the dispersion of the instantaneous electronic response is measured in the spectral range between 411nm and 1064nm.
Identifier: CFE0004052 (IID), ucf:49141 (fedora)
Note(s): 2011-08-01
M.S.
Optics and Photonics, Other
Masters
This record was generated from author submitted information.
Subject(s): CS2
carbon disulfide
n2
Z-scan
Zscan
nonlinear refractive index
Persistent Link to This Record: http://purl.flvc.org/ucf/fd/CFE0004052
Restrictions on Access: public 2011-07-01
Host Institution: UCF

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