KTP / S-KTP crystals
Potassium Titanyl Phosphate (KTiOPO₄), KTP, is to one of the most commonly used nonlinear optical crystals with excellent nonlinear and electro-optic properties.
It is often referred to as S-KTP, Super Potassium Titanyl Phosphate.
KTP (S-KTP) is is the most efficient frequency doubling crystal for Nd:YAG and Nd:YVO4 and the best nonlinear crystal for 1064nm pumped OPOs.

KTP / S-KTP crystal strengths include:
  • Excellent nonlinear optical and electro-optic coefficients
  • Wide phase-matching acceptance angle
  • Broad temperature and spectral bandwidth
  • High optical damage threshold

KTP / S-KTP crystal applications include:
  • SHG: middle and high power Nd: lasers @1064nm
  • Optical Parametric Amplifiers (OPA) and Oscillators (OPO)
LBO Crystal - Availability
  • Format:
Rods, Discs and Slabs
  • Sizes:
Diameter: 12mm max and Length: 25mm max
KTP / S-KTP Crystal Properties
Optical Properties Units Value
Transmission/
Transparency Range
µm 350 - 3500
Optical Homogeneity (δn) cm‾¹
Refractive Index (n)
@1064nm nx=1.7377, ny=1.7453 nz= 1.8297
@532nm nx=1.7780, ny=1.7886, nz= 1.8887
Non-linear Coefficients pm/V d31=1.95 pm/v, d32=3.9 pm/v,

d33=15.3 pm/v,d24=3.9 pm/v,

d15=1.95 pm/v
Effective Nonlinear Expressions: deff(II)= (d24-d15)sin2φsin2θ-(d15sin2φ+ d24cos2φ)sinθ = d32.cosφ (XY plane)
Electro-optic Coefficients: pm/V
Absorption Coefficient @1064nm cm‾¹ 0.001
Physical / Thermal Properties Units Value
Chemical Formula KTiOPO₄
Crystal Symmetry/
Structure
Orthorhombic
Space Group Pna21
Point Group mm2
Melting Point ºC 1172
Thermal Expansion Coeff. @20ºC 10‾⁶/ºC ┴19.0

║ 44
Thermal Conductivity Coeff. @20ºC W/m/ºK 2
Specific Heat Capacity cal./g K 0.1643
Density g/cm³ 3.01
Mohs Hardness 5
Optical Damage Threshold @1064nm,1ns GW/cm² c.19
KTP / S-KTP Crystal - Sellmeier Equations
nx2=3.0065+0.03901/(λ2-0.04251)-0.01327λ2

ny2=3.0333+0.04154/(λ2-0.04547)-0.01408λ2

nz2=3.0065+0.05694/(λ2-0.05658)-0.01682λ2
KTP / S-KTP Crystal - Common Configurations
Application/Operation Input
nm
Output
nm
Theta Phi
SHG (Type II) @1064nm (Nd:YAG) 1064 532 90 23.5
OPO (X-Cut) @1064nm (Nd:YAG) 1064 1570/

3300
90 0