LiInSe 2 nanosecond optical parametric oscillator tunable from 4.7 to 8.7 µm

Abstract

LiInSe 2 is one of the few (in the meanwhile 6) non-oxide nonlinear crystals whose band-gap (2.86 eV) and transparency enabled in the past nanosecond optical parametric oscillation in the mid-IR without two-photon absorption for a pump wavelength of 1064 nm. However, the first such demonstration was limited to the 3.34-3.82 µm spectral range with a maximum idler energy of 92 µJ at 3.457 µm for a repetition rate of 10 Hz. Now we achieved broadly tunable operation, from 4.7 to 8.7 µm, reaching maximum idler pulse energy of 282 µJ at 6.514 µm, at a repetition rate of 100 Hz (~28 mW of average power).

A multi-wavelength mid-IR laser based on BaGa4Se7 optical parametric oscillators

“…There are many approaches to achieving mid-IR lasers, such as chemistry lasers, free electron lasers, quantum cascade lasers, gas lasers, solid state lasers, fiber lasers, non-linear optical frequency conversion of optical parametric oscillator (OPO) and optical parametric amplifier (OPA), and so on [13][14][15][16][17]. Among them, OPO is a relatively easy method to obtain high energy, high power, and high beam quality, along with a relatively compact and wide tuning range [18][19][20][21][22][23][24].…”