Yu Zuhe

Observation of Optical Bistability Hysteresis Loop with Surface Waves in Doped Polymer Film

Optical bistability hysteresis loop has been observed experimentally with a setup using prism excitation of surface wave in a doped polymer thin film. A simple model has been developed to analyze its operation. The observed bistability hysteresis loop can be explained in terms of surface plasmon excitation and laser induced refractive index variations.

Observation of Beating Between Broadband Lights

We have observed beating between two broadband light sources of linewidths 4.3 and 2.3 nm by a method of time-delayed laser-induced double gratings. We explain the signal modulation by relating the signal intensity to the autocorrelation function of a field which consists of two frequency components.

Polarization Beats in a Cascade Three-Level System

Based on the interference between one-photon and two-photon processes, we report polarization beats in a cascade three-level system (PBCTS). We performed PBCTS experiments in Na vapor, which showed a modulation of the four-wave mixing signal intensity with period 55 fs, corresponding to the beating between the resonant frequencies of the transitions from 3S1/2 to 3P3/2 and from 3P3/2 to 4D3/2,5/2.

Energy-Level Splitting Measurement by Time-Delayed Laser-Induced Double Gratings

We have studied theoretically a time-delayed laser-induced double gratings (TDLIDG) in a Doppler-broadened three-level system. We have shown that the overall accuracy of using TDLIDG for the energy-level splitting measurement is determined by the homogeneous linewidths of the optical transitions.

Time-Delayed Raman-Enhanced Nondegenerate Four-Wave-Mixing Experiments with Incoherence Light in Carbon Disulfide

We report for the first time an experiment of the time-delayed Raman-enhanced non-degenerate four-wave-mixing (RENFWM) with incoherence light in carbon disulfide. We studied the RENFWM signal intensity as a function of the relative time delay ? between two beams which originate from a single broadband laser source. Our results indicate that the temporal behavior of the RENFWM is asymmetric with the maximum of the signal shifted from ??=?0. From our experimental results the relaxation time of the Raman mode can be extracted directly.

KNbO3: Fe Optical Frequency Discriminator

By using the feature that KNbO3: Fe has fast response time, we demonstrate a KNbO3: Fe optical frequency discriminator (KOFD) which is based on the method of time-delayed laser-induced double gratings. This KOFD can be used to measure the frequency difference between two laser fields.

Observation of collisional narrowing by time-resolved degenerate four-wave mixing in sodium

The first observation of collisional narrowing by time-resolved degenerate four-wave mixing has been reported. The velocity-changing collision cross section of Na in Ar we obtained is 5.6×10-15cm2.