KTP Crystal

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.

  • Crystal Structure: Orthorhombic
  • Melting point: 1172°C
  • Curie Point: 936°C
  • Lattice parameters: a=6.404Å, b=10.615Å, c=12.814Å, Z=8
  • Temperature of decomposition: ~1150°C
  • Transition temperature: 936°C
  • Density: 2.945 g/cm3
  • Product Detail

    Technical parameters


    Potassium Titanyl Phosphate (KTiOPO4 or KTP) KTP is the most commonly used material for frequency doubling of Nd:YAG and other Nd-doped lasers, particularly when the power density is at a low or medium level. To date, extra and intra-cavity frequency doubled Nd:lasers using KTP have become a preferred pumping source for visible dye lasers and tunable Ti:Sapphire lasers as well as their amplifiers. They are also useful green sources for many research and industry applications.
    KTP is also being used for intracavity mixing of 0.81µm diode and 1.064µm Nd:YAG laser to generate blue light and intracavity SHG of Nd:YAG or Nd:YAP lasers at 1.3µm to produce red light.
    In addition to unique NLO features, KTP also has promising E-O and dielectric properties that are comparable to LiNbO3. These advantaged properties make KTP extremely useful to various E-O devices. 
    KTP is expected to replace LiNbO3 crystal in the considerable volume application of E-O modulators, when other merits of KTP are combined into account, such as high damage threshold, wide optical bandwidth (>15GHZ), thermal and mechanical stability, and low loss, etc.
    Main Features of KTP Crystals:
    ● Efficient frequency conversion(1064nm SHG conversion efficiency is about 80%)
    ● Large nonlinear optical coefficients(15 times that of KDP)
    ● Wide angular bandwidth and small walk-off angle
    ● Broad temperature and spectral bandwidth
    ● High thermal conductivity (2 times that of BNN crystal )
    ● Frequency Doubling (SHG) of Nd-doped Lasers for Green/Red Output
    ● Frequency Mixing (SFM) of Nd Laser and Diode Laser for Blue Output
    ● Parametric Sources (OPG, OPA and OPO) for 0.6mm-4.5mm Tunable Output
    ● Electrical Optical(E-O) Modulators, Optical Switches, and Directional Couplers
    ● Optical Waveguides for Integrated NLO and E-O Devices a=6.404Å, b=10.615Å, c=12.814Å, Z=8

    Basic Properties of KTP
    Crystal structure Orthorhombic
    Melting point 1172°C
    Curie Point 936°C
    Lattice parameters a=6.404Å, b=10.615Å, c=12.814Å, Z=8
    Temperature of decomposition ~1150°C
    Transition temperature 936°C
    Mohs hardness »5
    Density 2.945 g/cm3
    Color colorless
    Hygroscopic Susceptibility No
    Specific heat 0.1737 cal/g.°C
    Thermal conductivity 0.13 W/cm/°C
    Electrical conductivity 3.5×10-8 s/cm (c-axis, 22°C, 1KHz)
    Thermal expansion coefficients a1 = 11 x 10-6 °C-1
    a2 = 9 x 10-6 °C-1
    a3 = 0.6 x 10-6 °C-1
    Thermal conductivity coefficients k1 = 2.0 x 10-2 W/cm °C
    k2 = 3.0 x 10-2 W/cm °C
    k3 = 3.3 x 10-2 W/cm °C
    Transmitting range 350nm ~ 4500nm
    Phase Matching Range 984nm ~ 3400nm
    Absorption coefficients a < 1%/cm @1064nm and 532nm


    Nonlinear Properties
    Phase matching range 497nm – 3300 nm
    Nonlinear coefficients
    (@ 10-64nm)
    d31=2.54pm/V, d31=4.35pm/V, d31=16.9pm/V
    d24=3.64pm/V, d15=1.91pm/V at 1.064 mm
    Effective nonlinear optical coefficients deff(II)≈ (d24 – d15)sin2qsin2j – (d15sin2j + d24cos2j)sinq


    Type II SHG of 1064nm Laser
    Phase matching angle q=90°, f=23.2°
    Effective nonlinear optical coefficients deff » 8.3 x d36(KDP)
    Angular acceptance Dθ= 75 mrad Dφ= 18 mrad
    Temperature acceptance 25°C.cm
    Spectral acceptance 5.6 Åcm
    Walk-off angle 1 mrad
    Optical damage threshold 1.5-2.0MW/cm2