This paper introduces the recent development of our integrated optical addressed spatial light modulator and its applications in the high power laser systems. It can be used to convert the incident beam into uniform beam for high energy effiency, or it can realize special distribution to meet the requirements of physical experiment. The optical addressing method can avoid the problem of the black matrix effect of the electric addressing device. Its transmittance for 1053nm light is about 85% and the aperture of our device has reached 22mm× 22mm. As a transmissive device, it can be inserted into the system without affecting the original optical path. The applications of the device in the three laser systems are introduced in detail in this paper.
In the SGII-Up laser facility, this device demonstrates its ability to shape the output laser beam of the fundamental frequency when the output energy reaches about 2000J. Meanwhile, there’s no change in the time waveform and far field distribution. This means that it can effectively improve the capacity of the maximum output energy.
In the 1J1Hz Nd-glass laser system, this device has been used to improve the uniformity of the output beam. As a result, the PV value reduces from 1.4 to 1.2, which means the beam quality has been improved effectively.
In the 9th beam of SGII laser facility, the device has been used to meet the requirements of sampling the probe light. As the transmittance distribution of the laser beam can be adjusted, the sampling spot can be realized in real time. As a result, it’s easy to make the sampled spot meet the requirements of physics experiment.
We present an optically addressed liquid crystal light valve based on a twisted nematic liquid crystal layer associated to a photoconductive BSO layer. Based on the optical addressing of a continuous layer of liquid crystal, the spatial transmittance distribution of 1053nm coherent light through the light valve has a corresponding relationship with the intensity distribution of 470nm incoherent light projected onto the photoconductive BSO layer. This relationship has been studied experimently. As a transmissive device, it has the advantage of high transmittance and it can overcome the problem of black-matrix effect. The aperture of our device has reached 22mm× 22mm.
In high-power laser system, in order to extend the components' service life and reduce the operation costs, more
attentions should be pay at the research for damages ablation at multi-layer optical components and other high load
optical components. 240ps, 35ps, 6ps 1053nm laser pulses has been used to investigate damage ablation and damage
resistant experiments at 0° high reflection films. By comparing the damage morphology and damage resistant threshold
of the ablation pits at different pulses width, it was superior to use ultra-short pulse to repair multi-layers optical
components. It was found that the shorter pulse width has been used, the higher the damage resistant threshold and the
lower the laser modulation. Furthermore, the finite-difference time-domain method was used to simulate the
electric-field intensification within the large size damage region of multilayer films.