Ma Zuguang

Reduction of Light Group Velocity by Coherent Population Oscillation in a Ruby Crystal

We report the investigation of the reduction of the group velocity propagation resulting from the steep change of the refractive index by the coherent population oscillation in a ruby crystal at room temperature. Slow light propagation is observed in a solid-state material at room temperature. The measured delay is about 2.314±0.005 ms, corresponding to a group velocity as slow as 43.215±0.094 m/s in a non-sinusoid modulated waveform. The influences of pulse duration on the delay and the reduction of light propagation are given.

Filter Performance of a Cesium Faraday Optical Filter at 852 nm

We have investigated a cesium Faraday filter at 852nm in relatively weak and strong magnetic fields, theoretically and experimentally. With a cesium cell of 0.02m length in an axial magnetic field of 0.06T, the line-centre operation has been achieved. The calculated peak transmission reached 99% with a full width at half maximum (FWHM) bandwidth of only 3.9 GHz. The measured FWHM bandwidth of the filter is 3.29 GHz, which is in general agreement with the theoretical result.

Observation of a cone radiation in sodium vapor

This paper reports the observation of a yellow cone radiation in sodium vapor pumped by an UV dye laser. It is proposed that a Raman resonant spontaneous four wave parametric process is generated and a doublet emission on resonant transition of 3p‐3s is induced.

Stimulated electronic Raman scatterng in sodium vapor

The observation of a stimulated electronic Raman scattering (SERS) on 3s–4s transition in sodium vapor pumped by a PTP dye laser is reported. Infrared output (Stokes) tunable from 2.38 μm to 2.65 μm has been obtained as the dye laser is tuned from 334.0 nm to 338.8 nm. Maximum photon conversion efficiency is about 30%.

Observation of the SRS spectrum of secondary vibrational foundamental frequency ν2 in CH4

With a Q‐switching Ruby laser, the stimulated Raman vibrational line ν of CH4, which was much difficult to observed, was first observe and the scattering feature between CH4 and H2 was compared.

Pulsed laser oscillation in the B 1Πu → X 1Σ+g transition of Na2 pumped by a dye laser

The pulsed laser oscillations at 525.9 nm, 530.0 nm and 541.4 nm in the B 1Πu → X 1Σ+g transition in Na2 pumped by a dye laser at 488.00 nm are first obtained with a plane‐plane resonator in the temperature range of 580 °C–720 °C. The pulsed laser oscillations are also observed by using other pumping wavelengths.

Na2 13Σ+g→13Σ+u lasing with peak around 892.0 nm

The first laser oscillation of Na2 13Σ+ig→13Σ+u transition has been obtained by using UV dye laser in the range of 337.0 nm to 342.0 nm. The cavity effect, small beam divergence (7 mrad), the pump energy threshold (∼80 μJ) and the narrowing linewidth have been observed in this experiment.

Observation of two quasi-static wings of laser-induced collision energy transfer

We investigate experimentally laser-induced collision energy transfer for transitions both from Eu(6s6p)8P9/2 to Sr(5s10s)1S0 and from Eu(6s6p)8- P7/2 to Sr(5s8d)1D2. Two quasi-static wings are observed in their excited function spectra. By using two dipole-dipole interactions, a spectral line from numerical calculation is consistent with the experimental line in two quasi-static wings.

Numerical study of laser-induced inelastic collisions in Cs-Sr

Two LICET transitions in Cs-Sr systems are suggested and the results of numerical calculations of the transition probability and collisional crosssection are obtained respectively from our four-level model and the conventional three-level model. Comparisons of these results prove the theoretical prediction that if the frequency difference ω21, is comparable to ω43, the three-level theory has great error in describing the LICET transition, while the four-level theory can describe all cases of LICET process perfectly.Two LICET transitions in Cs-Sr systems are suggested and the results of numerical calculations of the transition probability and collisional crosssection are obtained respectively from our four-level model and the conventional three-level model. Comparisons of these results prove the theoretical prediction that if the frequency difference ω21, is comparable to ω43, the three-level theory has great error in describing the LICET transition, while the four-level theory can describe all cases of LICET process perfectly.

Strained InGaAs/AlGaAs double quantum well laser with GRIN-SCH

Strained InGaAs/AlGaAs double quantum well lasers with two pairs of GRIN heterostructures have been fabricated by Metal-Organic Chemical Vapor Deposition (MOCVD). Its wavelength ranges from 970 to 982 nm, threshold current density is 140 A/cm/sup 2/ at room temperature CW operation. 520 mw/facet and 1.49 w/facet for CW output optical power has been obtained under 0.9 A and 2.0 A operation, respectively. The maximum CW output optical power can come up to 2.4 w/facet.