The Reserch Of Frequency Locked About 2-μm Laser

The 2-micron laser has particular characters. It is the preferred lamp-house of the imaging LIDAR ,the coherent Doppler LIDAR for wind sensing and the DIAL for measuring change of the depth and the temperature of earthly atmosphere. The lamp-house of LIDAR are always composed of one power oscillator and one seed laser. Seed laser is also called master oscillator. It is provided with low power, narrow linewidth, single frequency, stable laser. Inject seed laser to a power oscillator to obtain high power, narrow linewidth, single-mode, stable frequency laser. In this paper, we use the laser diode pumped Tm,Ho:YLF to achieve injection-locking laser of 2-micron .Theoretically, this paper analyzes the theory of injection-locking. To achieve injection-locking laser, the mode of seed laser and power oscillator must match. The seed laser must be single frequency, stable, narrow linewidth and sufficing some power. Then, analyze the hallmark of spectrum and so on.Experimentally, firstly, in view of the important of seed laser, at low temperature, we achieve perfect seed laser by using Tm,Ho:YLF microchip. The seed laser is stable, single-mode, 2067nm. The output power is up to 32.8mW. Secondly, we research the modes matching. It directly effects the frequency-locked. Both departure from angle and departure from axis can take difficult to the injection-locking. But the latter is more important. Thirdly, we design ring laser to carry out frequency-locked. When inject the seed source into the slaver oscillator through the output coupler, and unidirectional operation can be induced. The time of pulse build-up is shorter. The pulse width is narrower. The output pulse is more stable. Discuss the pulse energy and pulse width change by pump power. Making use of F-P interferometer method, we see more clearly about the mode inducing from seed laser to slaver oscillator.