Widely tunable, high-energy, mid-infrared (2.2-4.8 mu m) laser based on a multi-grating MgO:PPLN optical parametric oscillator

摘要

We designed a compact, widely tunable, high-energy, stable, mid-infrared optical parametric oscillator pumped by a conventional Q-switched Nd:YAG nano-second laser. The idler wavelengths were tuned from 2.2 to 4.8 mu m through gratings and temperature control of the multi-grating MgO-doped periodically poled lithium niobite (PPLN) crystal. A maximum idler output energy of 2.15 mJ was obtained at a pump energy of 21 mJ, which corresponded to an optical-optical efficiency in excess of 10%. A broad-spectrum bandwidth of 21 nm of idler radiation in the mid-infrared wavelength range was considered the result of the large grating period of the PPLN crystal.