KTP

Potassium Titanyl Phosphate (KTiOPO4 or KTP) is widely used in both commercial and military lasers including laboratory and medical systems, range-finders, lidar, optical communication and industrial systems.

Main Features of KTP Crystals:

  • Large nonlinear optical coefficient;

  • Wide angular bandwidth and small walk-off angle;

  • Broad temperature and spectral bandwidth;

  • High electro-optic coefficient and low dielectric constant;

  • Large figure of merit;

  • Nonhydroscopic, chemically and mechanically stable.

Basic Properties:

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
Mohs hardness
»5
Density
2.945 g/cm3
Hygroscopic Susceptibility
No
Specific heat
0.1737 cal/g.°C
Thermal conductivity
0.13 W/cm/°C
Electrical conductivity
3.5x10-8 s/cm (c-axis, 22°C, 1KHz)
Thermal expansion coefficients
a1 = 11 x 10-6 °C-1
a2 = 9 x 10-6 °C-1
a= 0.6 x 10-6 °C-
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
Phase matching range
497nm – 3300 nm
Nonlinear coefficients
 (@ 1064nm)
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



Applications:

  • 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

Technical Parameters:

  • Dimension tolerance:(W±0.1mm)x(H±0.1mm)x(L+0.5/-0.1mm)(L≥2.5mm)
                                    (W±0.1mm)x(H±0.1mm)x(L+0.1/-0.1mm) (L<2.5mm)
  • Clear aperture: central 90% of the diameter
     No visible scattering paths or centers when inspected by a 50mW green laser
  • Flatness: less than λ/8 @ 633nm
  • Transmitting wavefront distortion: less than λ/8 @ 633nm
  • Chamfer≤0.2mm@45°
  • Chip:≤0.1mm
  • Scratch/Dig code: better than 10/ 5(MIL-PRF-13830B)
  • Parallelism: better than 20 arc seconds
  • Perpendicularity: ≤5 arc minutes
  • Angle tolerance: △θ≤0.25°, △ф≤0.25°
  • Damage threshold [GW/cm2 ]:>0.5 for 1064nm, TEM00, 10ns, 10HZ (AR-coated)
                                                  >0.3 for 532nm, TEM00, 10ns, 10HZ (AR-coated)