SL212 laser is excellent solution for applications, where high energy picosecond pulses are needed. In contrary to conventional mode-locked lasers the SL212 series lasers use different method of generating short pulses based on backward-stimulated Brillouin scattering (SBS). Diode pumped passive Q-switched single longitudinal mode (SLM) nanosecond generator is the heart of the system. It provides nanosecond optical pulse that is later compressed during SBS in a special cell.
Pulse compressor consists of optical guiding system and SBS-cell. SBS cell is designed for safe and longlife maintenance free operation. A linearly polarized light pulse from master oscillator passes through QWP and is focused into SBS-cell by lens. Focusing is arranged in the way to compress the pulse via SBS process. The backscattered Stokes pulse, as its phase is reversed, strictly repeats the path of pump pulse in the opposite direction and with a reversal divergence. The compressed pulse is guided into the amplification stage using polarizer and mirror.
After SBS compression, pulse is directed to multi-pass flashlamp pumped power amplifier system, providing high-energy pulses. SL212 model lasers use multi-pass amplifier system which is based on laser chamber containing Nd:YAG rod pumped by two flash lamps. For smooth obtaining output beam profile pre-amplifier and double-pass amplifier layout is used in SL212 series lasers. Power amplifier includes optical components arranging passes through the active element. Aperture is employed to prevent the returning depolarized radiation from getting back into the amplifier.
Thermocontrolled harmonics’ generators, based on angle-tuned non-linear crystals and harmonic separation optics are available as standard options. Fundamental and second harmonics are separated and has a single output port. Harmonics’ crystals mounted in temperature‑controlled heaters. Pulse compression during SBS, is a simple and cost effective way for generating high power picosecond pulses. In addition to it, SBS compression allows generation of pulses with exceptional pulse duration range: from 150 ps up to 1000 ps. A power supply and water/water type cooling units, placed in standard 19” rack, requires a little space under the user’s optical table.