Abstract

Currently lasers are perceived as unique light that can produce specific states of matter through selective manipulations that could not be realized using any other conventional incoherent addition of thermal or electronic energy to a system. Although the selective laser chemistry is still a dream, the selective control of material processing done by optimization of laser intensity, as well as the temporal, spatial and spectral characteristics of the laser radiation is frequently used to move some contemporary technologies beyond their limits. For instance, in various systems efficient light-matter interactions require optical pulses much shorter than the thermal and acoustic confinement times of materials and sufficiently high pulse energies to perform material manipulation or ablation [1]. In addition, the average power of the lasers has to be large enough (×10-100 W) to enable “high throughput” and useful product yields. Thus reliable high-energy (>10 mJ) laser systems with high-peak power (>10 MW) pulses at kHz repetition rates, having diffraction-limited beams are of fundamental interest for both scientific, industrial and defense applications, including material processing and synthesis, various LIDARs, chemical sensing, highly efficient nonlinear frequency conversions, etc. Many of these applications require the temporal profile of the laser output to be a burst of picosecond pulses or a single smooth sub-nanosecond pulse. However, the majority of the existing kHz nanosecond laser systems emitting in the near-infrared spectral region around 1 micron have output energy below few tens of mJ, where the repetition rate does not exceed 10-100 Hz and beam profile is far from single TEM00 mode.

© 2017 IEEE