Grating Splicing Technology Research

To obtain high-energy peak power laser pulse with chirped pulse amplification (CPA) technology is currently the best option. Grating compressor system as a laser system the smallest components of damage threshold directly limits the output energy. PW laser systems need a meter-aperture grating. Therefore, large aperture grating production is very urgent. It is difficult to achieve a monolithic large grating directly, and explore other methods to obtain large aperture gratings. The common method is a multi-block grating splicing or holographic technology tiling. For the high required precision of tiled grating, in the results of previous studies, it is raised that the real-time monitoring and adjusting the rotation of tiled gratings assures the high precision and stability. More comprehensive study about tiled gratings:1,Retrospect the characteristic,application gratings and development of diffraction gratings, and introduce the overseas fruits. Analyzing two typical methods of large mosaic gratings.2,Analyzing the impact of space-time characteristics on beam after the tiled gratings and discussing of the control-precision.3,The manual tiled experiment is used to verify the feasibility of tiling, in this base the experiment of real-time monitoring and adjusting rotation was done. Designing the detection devices and fine-tuning devices of tiled gratings. Therefore, using a zero-order and first-order ray to monitor the rotation error independently, 0.1 pixels can be achieved in sub-pixel accuracy by quadratic curve-fitting measuring the center of fringe and it can detect about 0.5μrad rotation error. For the requirements of high precision confined by the controlling device and environment, real-time monitoring and adjusting is used to maintain the posture grating, and feedback the deflection to the installations to maintain the tiled grating position. It can be maintained the deviation within 0.5μrad long. Experiments show it to meet precision and prolonged stability requirements that rotation error real-time monitor and adjust about tiled gratings.4,Using the results of previous studies, and analyzing the probe laser theoretical principle and the light wavelength. The change of main laser's wavelength and work-angleleads to the phase difference, and calculate the control-accuracy. Designing corresponding tothe tiled grating optical detection program.