Experimental research on an arbitrary pulse generation system for imaging VISAR

Imaging VISAR is an important diagnostic tool for a variety of shock-related phenomena in laser-driven experiments. To adapt to various types of shaped driven pulse, the imaging VISAR needs an illuminating light with good shaping capability. Here, a flexible laser probe system was experimentally studied. Being generated from a 1064-nm DFB laser, the continuous wave was modulated by a waveguide amplitude modulator driven by 10 GS/s arbitrary waveform generator. After being amplified by fiber amplifiers and Nd:YAG rod amplifiers, the signal pulse was frequency-converted to 532-nm green light by a thermally controlled LBO crystal with a final output energy larger than 10 mJ. Finally, the green light was coupled into a 1-mm core diameter, multimode fused silica optical fiber and propagated to the imaging VISAR. The probe laser could realize accurate pulse shaping with time resolution below 100 ps. Uniformity in intensity and capability of arbitrary pulse shaping provides great convenience for the analysis of experimental data.