Side-pumped, high beam-quality Nd:YLF amplifier for LIDAR applications

We are constructing a Q-switched, frequency doubled Nd:YLF laser for pollution measurements in the Amazon Basin using the LIDAR technique. The laser should be very compact, robust and must present a good beam quality for efficient second harmonic generation. Our approach is a Nd:YLF MOPA based on four diode side-pumped modules (see figure 1), one for the oscillator and three for the amplifier. For compactness we use a Cr/sup 4+/ saturable absorber as q-switcher. We conclude that our compact cavity design permits efficiency equal to other related works and power scalability while maintaining good beam quality.