Xizhang Luo

Study on spectral characteristics and operating parameters of optically pumped NH/sub 3/ FIR cavity laser

By solving the density matrix equations of a quantum system and taking into account the multibeam interference characteristics of a Fabry-Perot cavity, the output power density of an optically pumped NH/sub 3/ far-infrared (FIR) cavity laser was calculated by means of the iteration method. Based on the calculations, the spectral characteristics and operating parameters of the laser were studied. Experimentally, by using inductive metallic meshes as reflectors and couplers, a series of FIR cavity lasers with a sample tube of 10, 20, and 100 cm in length were designed and constructed, and the emissions of the NH/sub 3/ cavity lasers pumped by a TEA-CO/sub 2/ laser with a 10R(8) or 9R(16) line were measured. The experimental results were in good agreement with theoretical calculations.

Spikes in Raman spectrum of miniature optically pumped NH3 FIR laser

In this paper, the semiclassical density matrix equation was solved to calculate the spectral characteristics of V2:a--sR(0,0) transition in a miniature optically pumped NH3 far infrared laser (mini-NH3-OPFIRL), which was pumped by CO2-10R(6) line. The results of theoretical calculation showed that the spikes in Raman spectrum of V2:a--sR(0,0) would appear when the operating NH3 gas pressure was higher than a certain critical value or pumping power density was lower than a certain critical value, which was caused by Raman processes interaction of AC-Stark splitting. In our experiment, 298 µm FIR spetral line of a--sR(0,0) pumped by a TEA-CO2 laser with 10R(6) line was observed but the spikes could not be observed owing to the limitation of the resolution of the F-P interferometer.

Interaction of multi-raman-processes in miniature optically pumped NH3 fir laser

The principle of Raman gain superposition was introduced to the theory of multi-Raman- processes interaction. Spectral characteristics of Raman lines from miniature NH3-optically pumped FiR lasers were studied and measured.

Operating parameter optimization of optically pumped CH3OH far-infrared laser

By solving the density matrix equations of a quantum system, the output power intensity of an optically pumped CH3OH FIR laser (CH3OH-OPFIRL) was calculated by means of iteration method, and the spectral characteristics were got. Base on the calculation, optimization of operating parameters including operating gas pressure, pumped power and output coupling coefficient of the CH3OH cavity laser were systematically studied. Experimental, a series of FIR emissions of the CH3OH cavity laser pumped by TEA-CO2 laser with 9P(16) line were measured. The experimental results were in good agreement with theoretical calculations.

Experimental study on miniature pulsed CH3OH far-infrared laser

Using a grating tuned TEA-CO2 laser with 9P(16) line to pump a 10cm or 20cm long miniature Fabry-Perot cavity CH3OH laser, pulsed far infrared(FIR) lines of 570.6um and 918um wavelengths were observed, the latter is a new line. Operation performance and spectral characteristics of the miniature CH3OH laser were studied.

The study of the interaction of Raman processes in miniature optically pumped cavity fir laser

The gain superposition principle (GSP) for optically pumped FIR laser was proposed, and the interaction of Raman processes was proven to be the inevitable result of the GSP, The GSP was well verified in our miniature optically pumped cavity FIR laser experiments. The calculated and experimental results were discused in detail.

Theoretical Study of Optimum Operation of Two-Longitudinal-Mode Optically Pumped Miniature FIR Laser

Based on the semi-classical density matrix equation, the optimum operation of two-longitudinal-mode optically pumped miniature FIR laser was studied theoretically. The relations and the contributions to FIR laser output power of the laser structural parameters and operating parameters were calculated and discussed.

The Optimum Operation of an Unified Mini-Optically Pumped NH3 Submillimeter Wave Laser

An unified miniature optically pumped NH3 submillimeter wave laser (OPSMMWL), including a mini TEA-CO2 pump laser, was developed. It lased successfully with coherent emission at 67.2μm, 90.4μm and 151.5μm. The optimum operation of the unified mini-OPSMMWL was studied experimentally and the relations among SMMW laser output power, operating gas pressure, length and coupling condition of the cavity were measured. It has been found that buffer gas N2 has significant effect on 67.2μm and 151.5μm emissions and very wide band SMMW laser emission was a common feature of the mini-OPSMMW cavity laser.

Spectral Characteristics of Miniature Two-Longitudinal-Mode Optically Pumped FIR Laser

With the assumption that the pump source was two-longitudinal-mode, the semiclassical density matrix equation of a three-energy-level system was solved. By means of iteration method, the spectral characteristics of miniature two-longitudinal-mode optically pumped NH3 far-infrared cavity laser, which was pumped by CO2-9R(16) line, were calculated numerically. The influences of operating parameters on laser spectrum were studied intensively.

The tuning characteristics of optically pumped fir cavity laser

Based on the quantum mechanics theory of density matrix and the principle of multiple-beam interference, the tuning characteristics of optically pumped NH3 FIR lasers were studied. A series of metallic mesh Fabry-Perot cavity lasers with sample tubes of 10cm, 20cm and 100cm in length were constructed and operated successfully, and the FIR laser spectra of the NH3 cavity lasers pumped by a TEA-CO2 laser were measured.