AgGaS2 Crystals

  • Wavefront distortion: less than λ/6 @ 633 nm
  • Dimension tolerance: (W +/-0.1 mm) x (H +/-0.1 mm) x (L +0.2 mm/-0.1 mm)
  • Clear aperture: > 90% central area 
  • Flatness: λ/6 @ 633 nm for T>=1.0mm
  • Surface Quality: Scratch/dig 20/10 per MIL-O-13830A 
  • Parallelism: better than 1 arc min
  • Perpendicularity: 5 arc minutes
  • Angle tolerance: Δθ < +/-0.25o, Δφ < +/-0.25o
  • Product Detail

    Technical Parameters

    Test report


    AGS is transparent from 0.50 to 13.2 µm. Although its nonlinear optical coefficient is the lowest among the mentioned infrared crystals, high short wavelength transparency edging at 550 nm is made use of in OPOs pumped by Nd:YAG laser; in numerous difference frequency mixing experiments with diode, Ti:Sapphire, Nd:YAG and IR dye lasers covering 3–12 µm range; in direct infrared countermeasure systems, and for SHG of CO2 laser. Thin AgGaS2 (AGS) crystal plates are popular for ultrashort pulse generation in mid IR range by difference frequency generation employing NIR wavelength pulses.
    • Generation second harmonics on CO and CO2 - lasers
    • Optical parametric oscilator
    • Different frequency generator to middle infrared regions up to 12 mkm.
    • Frequency mixing in the middle IR region from 4.0 to 18.3 µm
    • Tuneable solid state lasers (OPO pumped by Nd:YAG and others lasers operating in 1200 to 10000 nm region with efficiency 0.1 to 10 %)
    • Optical narrow-band filters in the region near isotropic point (0.4974 m at 300 °K), transmission band being tuned at temperature variation
    • Up-conversion of CO2 laser radiation image into near-IR or visible region by using/ or use of Nd:YAG, ruby or dye lasers with efficiency up to 30 %


    Standard cross sections are 8x 8mm, 5 x 5mm, Crystal length range from 1 to 30 mm. Custom sizes are also available on request.


    Basic Properties
    Lattice parameters a = 5.757, c = 10.311 Å
    Non-linear coefficient at 10.6 um d36 = 12.5 pm/V
    Optical damage threshold at 10.6 um, 150 ns 10 – 20 MW/cm2
    parallel to c-axis 12.5 x 10-6 x °C-1
    perpendicular to c-axis -13.2 x 10-6 x °C-1
    Crystal Structure Tetragonal
    Cell Parameters a=5.756 Å, c=10.301 Å
    Melting Point 997 °C
    Density 4.702 g/cm3
    Mohs Hardness 3-3.5
    Absorption Coefficient 0.6 cm-1 @ 10.6 µm
    Relative Dielectric Constant @ 25 MHz ε11s=10 ε11t=14
    Thermal Expansion Coefficient ||C: -13.2 x 10-6 /oC ⊥C: +12.5 x 10-6 /oC
    Thermal Conductivity 1.5 W/M/°C
    Linear Optical Properties
    Transparency Range 0.50-13.2 um
    Refractive Indices @ 1.064 um @ 5.300 um @ 10.60um no 2.4521 2.3945 2.3472 ne 2.3990 2.3408 2.2934
    Thermo-Optic Coefficients dno/dt=15.4 x 10-5/°C dne/dt=15.5 x 10-5/°C
    Sellmeier Equations (ʎ in um) no2=3.3970+2.3982/(1-0.09311/ʎ2)+2.1640/(1-950/ʎ2) ne2=3.5873+1.9533/(1-0.11066/ʎ2)+2.3391/(1-1030.7/ʎ2)
    Nonlinear Optical Properties
    Phase-Matching SHG Range 1.8-11.2 um
    NLO Coefficients @ 1.064 um d36=d24=d15=23.6 pm/V
    Linear Electro-optic Coefficients Y41T=4.0 pm/V Y63T=3.0 pm/V
    Damage threshold @ ~ 10 ns, 1.064 um 25 MW/cm2(surface),500 MW/cm2(bulk)
    Technical Parameters
    Wavefront distortion less than λ/6 @ 633 nm
    Dimension tolerance (W +/-0.1 mm) x (H +/-0.1 mm) x (L +0.2 mm/-0.1 mm)
    Clear aperture > 90% central area
    Flatness λ/6 @ 633 nm for T>=1.0mm
    Surface Quality Scratch/dig 20/10 per MIL-O-13830A
    Parallelism better than 1 arc min
    Perpendicularity 5 arc minutes
    Angle tolerance Δθ < +/-0.25o, Δφ < +/-0.25o

    AGS (AgGaS2) crystal Transmission Spectra(After rough polishing)
    Test thickness=20.8mm(Final thickness=20mm)
    Transmission spectra of Type II uncoated AgGaS2 crystal. OPO pumped by 1030nm laser. ZnGeP201 AgGaS2 (AGS) crystal displays excellent bulk quality across the transmission range,expect for residual a ray absorption centered near 1.8um.Surface absorption may increase with time,but the behavior is now greatly improved over that earlier crystals.The phase matching and nonlinear optical properties of AGS allow various SFM/DFM interactions from the visible to Middle infrared. ZnGeP201

    AGS (AgGaS2) crystal Transmission spectra(Uncoated) Test thickness=1.60mm: ZnGeP201