11-mJ, 15-Hz single-frequency diode-pumped Q-switched Er, Yb:phosphate glass laser

A single-frequency diode-pumped Q-switched Er, Yb:phosphate glass laser that oscillates at an eye-safe 1.54etam wavelength has been developed for use in coherent Doppler lidar. A maximum TEM(00)-mode Q-switched output energy of 10.9 mJ and a relatively long pulse width of 228 ns were obtained at a repetition rate of 15 Hz by use of a modified 2-m-long telescopic cavity. Frequency stability of as high as +/-1.9-MHz standard deviation and a side-mode suppression ratio of more than 30 dB were also achieved.