Measurement of complex c(3) using DFWM with an imaged 2D phase grating

POLY 528

Shuo-Yen Tseng, sytseng@lps.umd.edu1, Yi-Hsing Peng1, Weilou Cao1, Younggu Kim1, Lisa Lucas2, Victor Yun2, Yongzhang Leng, yleng@lps.umd.edu2, Chi H. Lee1, Warren N. Herman1, and Julius Goldhar1. (1) Department of Electrical and Computer Engineering, Laboratory for Physical Sciences, University of Maryland, College Park, MD 20742, (2) Laboratory for Physical Sciences and Department of Electrical and Computer Engineering, University of Maryland, College Park, MD 20742
Characterization of both the magnitude and the phase of the third-order susceptibility, c(3), is important for potential device applications of a given nonlinear material. We present a simple optical arrangement for direct and coherent detection of DFWM signal utilizing a imaged two-dimensional (2-D) phase grating for characterization of the complex value of c(3). Laser fluctuation causes a nonlinear error and introduces an uncertainty in determining the exact order of nonlinearity of the nonlinear process. We demonstrate the linearization of laser fluctuation with a fused silica sample and a nonlinear polymer sample with strong third harmonic generation (THG). The phase of c(3) of a processable nonlinear polymer sample is also measured with this setup.