Degenerate frequency two beam coupling in organic media via phase modulation

Date of Award


Degree Name

M.S. in Electro-Optics


Department of Electro-Optics and Photonics


Advisor: Joseph W. Haus


The following research was born out of the observation of a counter-propagating beam (CPB) originating from the interaction of a pump beam and a Fresnel reflection inside an organic liquid held inside a fused silica cuvette. The strong influence on overlap with the Fresnel reflection is evidence for degenerate frequency two-beam coupling (TBC) via a transient phase grating. It is well known that TBC requires a phase shift between the fields and the induced grating which is supplied by the finite temporal response of the nonlinearity. TBC also requires a frequency shift between the interacting fields. For degenerate frequencies to couple, this shift must arise from self or cross phase modulation in the medium. In this work, we present a strong, degenerate frequency TBC in two organic systems using a single nanosecond beam where the probe is generated from the Fresnel reflection of the cuvette and the necessary phase and frequency shifts are the result of the thermo-optic effect and population redistribution. Its effect on the analysis of nonlinear transmission experiments and its relationship with Stimulated Rayleigh Bragg Scattering (SRBS) is also presented.


Light, Phase modulation, Nonlinear optics, Optics, Physics, Electromagnetism, two beam coupling, degenerate frequency, self-phase modulation, nonlinear optics, organic media, irradiance scan, two wave mixing, nonlinear transmission

Rights Statement

Copyright 2014, author