ИСТИНА

High peak power picosecond lasers are widely used in a variety of scientific, technological and medical applications such as time-resolved and time-domain nonlinear laser spectroscopy, coherent anti-Stokes Raman microscopy and two-photon bio-imaging, laser ablation and micromachining, photo-guns equipping in electron accelerator injectors, precise satellite and lunar laser ranging, aesthetic cosmetology and dermatology, clinical surgery etc. Then, practical and reliable, highly stable and compact picosecond laser schemes providing single pulse energy of mJ and multi-mJ level operating at different repetition rates, typically within kHz, are required to be developed. Key modern approaches are briefly observed. We develop advanced schemes of highly effective picosecond pulsed-periodic diode-pumped lasers of high peak and average power based on Nd-doped crystals. The schemes comprise active-passive mode-locked and negative feedback controlled master oscillators combined with regenerative and linear amplifiers. Problems of effective power scaling, generated mode structure analysis and enhancement, fast electro-optical operation control and Pockels cell crystals stability are discussed in the present paper. We realized approach to generation of high-peak-power picoseconds pulse bursts based on use of master laser and electro-optically controlled regenerative amplifier with partial radiation output. Regenerative amplifier allows to obtain submillijole level energy picoseconds pulse trains with profiled envelope shapes which can be further enhanced in output amplifier stage. The envelope profile can be specially shaped to compensate amplification decrease from the beginning to the end of the train that allows operation at near saturation regime and most effective use of pump power.