演讲摘要：

The emission wavelengths of 1.6μm and 2μm lie in the eye-safe bandwidth region. They have great potential applications in a wide range of fields such as medical diagnoses and therapy, photoelectric countermeasure, laser range finder, laser remote sensing and active imaging. Furthermore, they are effective pump sources of optical parametrical oscillators and optical parametrical amplifications to generate radiation further in the mid-infrared region. Here, researches on 1.6μm and 2μm laser developing in our group are summarized. First, a 1617 nm Er:YAG laser resonantly pumped by CW 1532 nm narrow linewidth laser diodes (LDs) was investigated. For CW operation, 7.73 W output powerwas achieved at 50.57 W incident pumping power, with an optical to optical conversion efficiency of 15.28%. The central wavelength and 3 dB spectral width of the output laser are 1616.46 nm and 0.044 nm, respectively. For Q-switching mode, a maximum energy of 7.82 mJ with 80ns pulse width at 500 Hz repetition rates was obtained, the output beam quality were 1.39 and 1.23 in x and y directions, respectively. Second, using1470-nm quasi-continuous wave LDs directly-pumped an U-shape resonator Er:YAG laser, a maximum pulse energy of 20.54 mJ at 1617 nm was obtained at 50 Hz PRF, with a pulse width of 52 ns, peak power of ~395 kW, and the optical to optical efficiencyof ~6%. The polarization extinction ratio of the output beam was about 24 dB, and the beam quality parameters were approximately 1.02 and 1.03. Third, we built up 100W-level all fiber thulium fiber lasers at 1915nm, 1940nm, 1980nmand1996nm. And we used them to pump an AO Q-switched Ho:YAP laser. More than 32W average power with 47ns pulse width at 20kHz repetition rates was obtained. The wavelength was about 2118nm, and the beam quality was 1.08 and 1.1. And 30W Ho:YAP laser output power with 67ns pulse width at 10kHz repetition rates was obtained, the slope efficiency was up to 72%. These were the highest ouput power report of Ho:YAP crystal. Fourth, an injection seeded single frequency Tm:Ho:LLF ring resonant laser was developed. 102mJ output with 101ns pulse width at 5Hz repetition rates was obtained, and the laser wavelength was 2053nm. Last,pulsed Tm:fiber laser was developed. 6.7mJ output energy with 142ns pulse width at 10kHz was obtained in a two-stage MOPA Tm:fiber system, and its wavelength was 2068nm. And we also developed short pulse 2μm laser, 21.5W average power with 1.25ps at 30MHz repetition rate was obtained, the central wavelength was about 1990nm. Longer wavelength mid-infrared lasers will be developed using above pumping source.