High repetition rate slab amplifier (HRRSA) is extraordinarily indispensable for the future fusion power plant, ultra-short laser, laser weapon, and so on. Thermal controlling is the decisive factor for the repetition rate and the output energy of the slab amplifier. For larger clear aperture HRRSA, flash-lamp pumped slab amplifier based on neodymium phosphate glass (Nd:glass) is chosen with the liquid cooling. The liquid coolant circulates across the Nd:glass and takes off the thermal induced in the pumping process. A novel liquid coolant (Series A) whose refractive index is the same with Nd:glass is proposed to alleviate the wavefront distortion induced by thermal. The chemical stability of the liquid coolant under high energy flash-lamp irradiation with 200 shots and under the irradiation of a 1053nm laser with 19 hours and 37 hours are experimented. The results show that the chemical stability of the liquid coolant is stable under irradiation.
The latest progress on high power laser facilities in NLHPLP was reported. Based on a high power laser prototype, damage behavior of 3ω optics was experimentally tested, and the key influencing factors contributed to laser-induced damage in optics were deeply analyzed. The latest experimental results of advanced precision measurement for optical quality applied in the high power laser facility were introduced. At last, based on the accumulated works of 3ω elements damage behavior status in our laboratory, beam expanding scheme was presented to increase the total maximum output 3ω energy properly and decrease the laser induced damage risking of ω optics simultaneously.
Non-line-of-sight (NLOS) optical scattering communication (OSC) is studied theoretically and experimentally. Making
use of single scattering propagation model, properties of NLOS optical scattering channel are simulated numerically under some
typical condition. The results show that the path loss of the channel is quite large, and becomes larger as apex angle of the transmitter
and receiver increases. The results also show that the pulse transmitted from the source is broadened significantly after propagating in
the NLOS optical scattering channel. It will limit the available bandwidth of the channel, and probably cause intersymbol interference
in digital communication systems. Moreover, some elementary experimental facilities of NLOS UV communications are constructed.
A UV digital communication system based on 254nm low pressure mercury lamp has been set up, and the BER of the system is about
~10<sup>-4</sup> when the transmitter apex angle is 60 degree and bit rate is 1200bits/s. and NLOS light propagation experiments were conducted
by exploiting a 370nm UV light-emitting diode (LED). With the progress of devices based on semiconductor in UV band, NLOS
optical scattering communication with small volume and low power may be achieved in future.