Nonlinear optical crystals LGS (LiGaS2)




Main properties

Compound LiGaS2
Transparency range, µm 0.33 – 11.6
Symmetry mm2
Band gap, eV 4.15
Nonlinear susceptibility, pm/V
(at 2.3 µm)

d33= -10.7
Absorption edge in the far-IR on 0.2 transparency level µm 92
THz 3.25
Optical Damage Threshold, MW/cm2
1064 nm
(t=14 ns)

Thermal conductivity k, WM/M°C 6-8 calc.
SHG cut off 1.47 - 7.53

The parameters of optical elements

Compound LiGaS2
Orientation accuracy, arc min < 30
Parallelism, arc sec < 30
Flatness 546 nm λ/4
Surface quality, scratch/dig 30/20


LGS is a very recently proposed IR new nonlinear materials with a wurtzite-type structure and UV transmission down to 0.32. OPO, OPA, DFG to obtain mid-IR.
Crystals of LiBC2 group are characterised by a set of important physical parameters, such as large band gap, low two photon absorption, wide transparency range, including THz window, low group velocity mismatch, high thermal conductivity, low anisotropy of thermal expansion coefficient, etc. which lead to effective use in tunable laser systems in wide spectral range.

We are able to provide suitable Anti-reflection / Protective, etc. coatings tailored to customer’s specifications, reflectivity curves are applied upon request.