50 mJ/pulse, electronically tuned Cr:ZnSe master oscillator power amplifier

We have developed an electronically tuned Cr:ZnSe master oscillator power amplifier with nanosecond pulse operation. The amplifier system produced a broad tuning range from 2.26 to 2.66 μm and an output energy exceeding 50 mJ was obtained over a tuning range of 100 nm. The maximum energy conversion reached 46.6% at a wavelength of 2.41 μm when the pump fluence was 1.4 J/cm2. In addition, we show that Cr:ZnSe is an excellent gain medium for pulsed laser amplifiers to obtain high pulse energy in the broad mid-IR region and high extraction efficiency under low input fluence of 100 mJ/cm2 order.