It is well known that for the air-based and space-based lasers, a higher efficiency means decreasing the required power and waste heat removal that the satellite must accommodate and the energy resources on the satellite is limited. Higher repetition rate and high pulse energy, narrow pulse width can provide faster data acquisition and an adequate higher signal-to-noise ratio.Conductively-cooled high repetition rate, high efficiency and high pulse energy with high beam quality laser output were the trends of the lasers used for air-based and spacebased environments.

Researchers at Shanghai Institute of Optics and Fines Mechanics (SIOM/China) have been developed and demonstrated a laser-diode-pumped high efficiency, high pulse energy and single-frequency oscillator and amplifier for potential space environment applications  using conductively-cooled heat removal.[APPLIED PHYSICS B-LASERS AND OPTICS.103(4),809-812,2011]

They reported a conductively-cooled, singlefrequency Q-switched Nd: YAG laser employing an oscillator- amplifier, featuring high efficiency, high pulse energy and narrow pulse width and high degree of polarization.The oscillator was a diode-pumped injection seeded single frequency laser achieved by using the resonance-detection technique in Q-Switching operation. Four zigzag Nd: YAG slabs were adopted in amplifier stage for minimizing thermal distortion and stress-induced birefringences which were used in many high-power solid-state laser designs.The laser provides an output pulse energy of 800 mJ with pulse duration of 11 ns and near 3× diffraction-limited beam at a repetition of 100 Hz with optical–optical efficiency over 18%. Finally, the degree of polarization was also measured and near 98%, this will improve the nonlinear conversion efficiency. This laser set new records for high efficiency,Q-switched pulse energy and for average power from laser diode-pumped lasers.