Crystals Materials
KTA Crystal for Optical Parametric Oscillation (OPO) applications
  • Transparent between 0.5μm and 3.5μm
  • High non-linear optical efficiency
  • Large temperature acceptance
  • Lower birefringence than KTP resulting in a smaller walk-off
  • Excellent optical and non-linear optical homogeneity
  • High damage threshold of AR-coatings: >10J/cm² at 1064nm for 10ns pulses
  • AR-Coatings with low absorption at 3μm available
  • Qualified for space projects
  • Potassium Titanyle Arsenate (KTiOAsO4), or KTA crystal, is an excellent nonlinear optical crystal for Optical Parametric Oscillation (OPO) application. It has better non-linear optical and electro-optical coefficients, significantly reduced absorption in the 2.0-5.0 μm region, broad angular and temperature bandwidth, low dielectric constants. And its low ionic conductivities result in higher damage threshold compared with KTP. KTA is often used as an OPO / OPA gain medium for emission in the 3μm range as well as an OPO crystal for eye-safe emission at high average power.

    Specifications of KTA Crystal
    Thickness/Diameter Tolerance ±0.05 mm
    Orientation Tolerence < 0.5°
    Size 3 mm ~ 150 mm or Upon customer request
    Dimension Tolerances ±0.05 mm
    Surface Quality 10/5 S/D per MIL-O-13830A
    Parallelism < 10 arcsec
    Perpendicularity < 5 arcmin
    Clear Aperture > 90%
    Wavefront Distortion λ/8 @ 633 nm
    Surface Flatness < λ/8 @ 632.8 nm
    Chamfer < 0.1 mm @ 45°
    Coating AR/HR/PR coating upon customer's request
    Physical and chemical properties
    Chemical Formula KTiOPO4
    Crystal Structure Orthorhombic, space group Pna21, point group mm2
    Lattice Constant a=13.125Å, b=6.5716Å, c=10.786Å
    Density 3.45 g/cm3
    Melting Point About 1130°C
    Thermal Conductivity (W/m/k@25°C) k1=1.8, k2=1.9, k3=2.1 W/m*K
    Hardness (Mohs) 5
    Optical and Nonlinear properties
    Transparency Range 350 nm - 5300 nm
    Absorption Coefficients < 0.05%/cm(@1064 nm),
    < 0.05%/cm(@1533 nm),
    < 5%/cm(@3475 nm)
    NLO Coefficients d31 = 2.76, d32 = 4.74, d33 = 18.5 , d15 = 2.3, d24 = 3.2
    Electro-optic coefficients r33=37.5; r23=15.4; r13=11.5
    SHG Phase Matchable Range 1083 nm - 3789 nm

    Stock specification list

    If need other specifications and quantities products, please contact us(
    Part Number Size Theta, θ Phi, φ Coating S1/S2 Application
    KTA-Cry-001 5x5x20 mm 45 0 AR@1064+(1500-4500) nm OPO@1064 nm
    KTA-Cry-002 6x6x3 mm 46 0 AR@1030+(1700-5000) nm OPO@1030 nm


  • AR/HR/PR coatings are available at your specified wavelength.
  • Be sure to wear laser safety goggles when checking optical path and adjusting optical axis.
  • KTA is relatively soft and therefore requires precautions to protect its polished surfaces.
  • When angle adjusting is necessary, keep in mind that the acceptance angle of KTA is small.
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