We demonstrated the arbitrary pulse shaping for a high power, joules class, and multi-pass ring Nd: glass laser amplifier system with nanosecond pulses based on the direct calculation method. While the square pulse with pulse energy 0.9mj and FWHM (full width at half maximum) pulse width 6ns, a 0.9J at 1Hz high power laser pulse energy is generated, which has the ability to change the waveform arbitrarily based on the full fiber front end. The laser amplifier system consists of three parts: full fiber seeder, diode pumped Nd: glass regenerative amplifier, and multi-pass ring amplifier. With the help of direct calculation method based on the input-output model, the input pulse shape has been calculated and the output pulse shape has been compared to the target pulse shape, showing that the simulation and experiment is consistent. Some other interesting pulse shapes have been produced with pre-compensated inject pulse based on the calculation which shows great potential to be applied in high power laser amplifier system with a desired pulse shape.
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.