ABSTRACT
Q-switched operation of a diode-side-pumped, conduction-cooled Tm,Ho:YLF laser oscillator with 100-mJ output at a pulse repetition rate of 20 Hz and an eye-safe wavelength of 2-µm was achieved. The noncomposite Tm,Ho:YLF laser rod was conduction-cooled down to -80°C through thermal contact of In films from Cu heat sinks, and the laser diode arrays were conduction-cooled to approximately 20°C using Cu heat sinks in a vacuum container. A ring resonator of 3.86 m length with an acousto-optic Q-switch was used. The pulse width was 125 ns, and optical-to-optical efficiency was approximately 7% for an output of 100 mJ. The laser is used at 2.05 µm for applications of Doppler wind lidar measurements, CO2 differential absorption lidar measurements, and aerosol profiling.
ABSTRACT
The generation of stable dual-wavelength pulses from an actively Q-switched Nd:YAG laser operating at 1064 and 1319 nm was demonstrated. Pulse energies of the dual-wavelength laser were extracted by two temporally separated stimulated-emission processes for a single pumping process, thereby avoiding line competition between the two laser transitions. Total energy of the order of 20 mJ was achieved for the two pulses, and the ratio of the pulse energies of the two lasers could be selected by adjusting the output couplings. The pulse-to-pulse fluctuations for the lasers operating at 1319 and 1064 nm were 4.7%-4.8% and 1.5%-2.6%, respectively, which were almost equivalent to those for a single emission line in our system. The experimentally observed laser performance agreed reasonably well with theoretical predictions.
ABSTRACT
We have developed a conductively cooled, Q-switched 2 µm laser with a triangular-prism Tm,Ho:LLF rod. Using a fused-silica acousto-optic Q-switch, the laser produced an output energy of 30 mJ in a single Q-switched pulse at a pulse repetition frequency of 5 Hz. Although the laser rod had polished lateral surfaces, no parasitic oscillation occurred, even at the maximum pumping level. In addition, broadly tunable laser performance was achieved with a birefringent filter plate under relatively large output coupling. The laser could be continuously tuned from 2051 to 2069 nm. Measured tuning characteristics were in reasonable agreement with calculated results.
ABSTRACT
A coherent 2 microm differential absorption and wind lidar (Co2DiaWiL) was developed to measure CO(2) concentration and line-of-sight wind speed. We conductively cooled a pumping laser head to -80 degrees C and diode arrays to approximately 20 degrees C. A Q-switched laser outputs an energy of 80 mJ (pulse width 150 ns (FWHM), pulse repetition frequency up to 30 Hz). CO(2) measurements made over a column range (487-1986 m) for 5 min accumulation time pairs achieved 0.7% precision. Line-of-sight wind speeds for ranges up to approximately 20 km and returns from a mountainside located 24 km away from the Co2DiaWiL were obtained.
ABSTRACT
A diode-pumped Tm, Ho:GdVO4 laser with a side-pumping configuration is demonstrated for the first time to our knowledge. Optimum Tm and Ho dopant concentrations for GdVO4 are somewhat lower than those for garnet and fluoride crystals. With a 3% Tm, 0.3% Ho:GdVO4 crystal an output energy of 31.2 mJ and a slope efficiency of 14.5% were obtained in normal-mode operation at room temperature.
