Nonlinear optical crystal AGS (AgGaS2)


(silver thiogallate)



Main properties

Compound AgGaS2
Transparency range, µm 0.47 – 13
Nonlinear coefficient, pm/V d36 = 12.6 @ 10.6 µm 
Negative uniaxial crystal no > ne (at λ < 0.497 μm ne > no)
Symmetry Tetragonal, -42m point group
Cell parameters, Å a=5.757, c=10.311

10.6 µm
5.3 µm
no=2.3475, ne=2.2918
no=2.3945, ne=2.3406
Optical Damage Threshold, MW/cm2
1064 nm
(t=10 ns)
Walk off angle, ° 5.3 µm 0.76
Thermal conductivity k, WM/M°C 1.5
Band-gap energy at room temperature, eV Eg = 2.73
Optical activity ρ = 522deg/mm at isotropic point n0= ne, λ = 0.4974 μm
Absorption edge in the far-IR on 0.2 transparency level 0.86 THz; 346 µm

The parameters of optical elements

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


  • Efficient frequency doubling for mid-IR radiation
  • Optical parametric oscilation and amplification, Different frequency generation to mid-infrared regions up to 12 µm
  • Optical narrow-band filters in the region near isotropical point (0.4974 µm at 300 K)

Large/long optical elements are available, please, send your requests.

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