Frequency-doubled Nd:YAG MOPA laser system with programmable rectangular pulses up to 200 microseconds

Abstract

A compact frequency-doubled diode-pumped Nd:YAG master-oscillator poweramplifier laser system with programmable microsecond pulse length has been developed. Analog pulse shaping of the output from a single-frequency cw Nd:YAG oscillator, and subsequent amplification, allowed the generation of rectangular pulses with pulse lengths on the order of the Nd:YAG fluorescence lifetime. Rectangular pulses of 1064 nm light with 520 mJ energy, 2.6 kW peak power, and 200 𝜇s duration, with linewidth below 10 kHz, were obtained at a repetition rate of 2 Hz. Second harmonic generation in a LBO crystal yielded pulses of 262 mJ and 1.3 kW peak power at 532 nm. The peak power can be maintained within 2.9% over the duration of the laser pulse, and long-term intensity stability of 1.1% was observed. The 532 nm beam is roughly Gaussian, with 𝑀 2 = 1.41 during the second harmonic generation. This system has potential as a pump source for titanium:sapphire, dye, or optical parametric amplifiers to generate tunable high-power single-frequency radiation.

Laser cooled molecules

“…However, the intensities available from current continuous wave lasers are probably not sufficient to produce these strong forces over the large spatial area needed to slow typical molecular beams. Current work by Beyer et al (2020) is seeking to fill this technological gap.…”