Persistent Link:
http://hdl.handle.net/10150/186881
Title:
Cascaded second-order nonlinearities in waveguides.
Author:
Sundheimer, Michael Lee.
Issue Date:
1994
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The cascaded second-order nonlinearity arising from the second-harmonic generation process in noncentrosymmetric media is a novel approach to achieving the nonlinear phase shifts required for all-optical signal processing. The research presented in this dissertation demonstrated and measured the cascaded second-order nonlinearity for the first time in viable integrated optical waveguide formats. Cascaded self-phase modulation was measured in potassium titanyl phosphate (KTiOPO₄ or KTP) segmented quasi-phasematched waveguides at wavelengths near 855 nm and in the optical fiber telecommunications window near 1.585 μm using picosecond and femtosecond pulses, respectively. Spectral modulation and broadening were observed on the output fundamental spectrum and compared to predictions from pulsed second-harmonic generation theory under conditions of group-velocity mismatch (temporal walk-off) and group-velocity dispersion. Peak cascaded phase shifts of the fundamental of approximately π at 855 nm were inferred with 690 W of peak guided power. Peak cascaded phase shifts of approximately π/2 were inferred at 1.585 μm with 760 W of peak power in the guide. Direct interferometric measurements of the magnitude and sign of the cascaded nonlinear phase shift of the fundamental were performed in temperature-tuned lithium niobate (LiNbO₃) channel waveguides at 1.32 μm. The cascaded phase shift was shown to change sign upon passing through the phasematching condition, as required by theory. Peak cascaded phase shifts of +0.53π and -0.13π were measured for 86 W peak power in these waveguides. A non-uniform temperature profile along the waveguide led to a non-uniform wavevector-mismatch along the guide, resulting in an enhanced positive phase shift and an increased temperature bandwidth for the phase shift. The phase shifts achieved in this research are large enough to be suitable for some all-optical signal processing functions.
Type:
text; Dissertation-Reproduction (electronic)
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Optical Sciences; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Stegeman, George I.; Burke, James J.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleCascaded second-order nonlinearities in waveguides.en_US
dc.creatorSundheimer, Michael Lee.en_US
dc.contributor.authorSundheimer, Michael Lee.en_US
dc.date.issued1994en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe cascaded second-order nonlinearity arising from the second-harmonic generation process in noncentrosymmetric media is a novel approach to achieving the nonlinear phase shifts required for all-optical signal processing. The research presented in this dissertation demonstrated and measured the cascaded second-order nonlinearity for the first time in viable integrated optical waveguide formats. Cascaded self-phase modulation was measured in potassium titanyl phosphate (KTiOPO₄ or KTP) segmented quasi-phasematched waveguides at wavelengths near 855 nm and in the optical fiber telecommunications window near 1.585 μm using picosecond and femtosecond pulses, respectively. Spectral modulation and broadening were observed on the output fundamental spectrum and compared to predictions from pulsed second-harmonic generation theory under conditions of group-velocity mismatch (temporal walk-off) and group-velocity dispersion. Peak cascaded phase shifts of the fundamental of approximately π at 855 nm were inferred with 690 W of peak guided power. Peak cascaded phase shifts of approximately π/2 were inferred at 1.585 μm with 760 W of peak power in the guide. Direct interferometric measurements of the magnitude and sign of the cascaded nonlinear phase shift of the fundamental were performed in temperature-tuned lithium niobate (LiNbO₃) channel waveguides at 1.32 μm. The cascaded phase shift was shown to change sign upon passing through the phasematching condition, as required by theory. Peak cascaded phase shifts of +0.53π and -0.13π were measured for 86 W peak power in these waveguides. A non-uniform temperature profile along the waveguide led to a non-uniform wavevector-mismatch along the guide, resulting in an enhanced positive phase shift and an increased temperature bandwidth for the phase shift. The phase shifts achieved in this research are large enough to be suitable for some all-optical signal processing functions.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairStegeman, George I.en_US
dc.contributor.chairBurke, James J.en_US
dc.contributor.committeememberShoemaker, Richard L.en_US
dc.identifier.proquest9507011en_US
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