Potassium dihydrogen phosphate (KDP) and potassium dideuterium phosphate (KD*P) crystals are functional


Potassium dihydrogen phosphate (KDP) and potassium dideuterium phosphate (KD*P) crystals are functional crystals that have received early attention and have been widely used in nonlinear optical materials. They can be used to amplify the power of Nd:YAG crystals at room temperature and have high electro-optic coefficients, making them ideal electro-optic crystals. They are commonly used in electro-optic modulators, Q switches, Pockels cells, and other applications.


Product features

Nonlinear optical coefficient is relatively low

Wide transparent range

Low loss

Good optical uniformity

Excellent temperature stability High damage threshold


Dimensional Tolerance (W±0.1 mm)×(H±0.1 mm)×(L±0.2 mm)
Angle Tolerance Dq<±0.3°, Df<± 0.3° 
Parallelism <20″
Perpendicularity <5′
Clear Aperture ≥Central 95% of the diameter
Surface Quality 10/5 (MIL-PRF-13830B)
Flatness λ/8 @633nm
Wavefront Distortion <λ/8 @633nm


Crystal Chemistry and Structural Characteristics
Crystal structure Orthorhombic
Lattice parameters a=7.45Å, b=7.45Å, c=6.68Å(KDP), c=12.96Å(DKDP)
Melting point 960℃(KDP), 149℃(DKDP)
Mohs hardness 2(KDP), 2.5(DKDP)
Density 2.35g/cm³
Thermal conductivity 1.1W/(m·K)
Thermal expansion coefficient

a:6.5×10-6/K, b:8.5×10-6/K, c:1.5×10-6/K(KDP)

a:6.6×10-6/K, b:8.6×10-6/K, c:1.5×10-6/K(DKDP)


Characteristic Parameters
Transmittance >90%(1064nm)
Optical uniformity <0.1%
Temperature stability <10-5/K
Nonlinear optical coefficient d36=0.39(pm/V)(KDP), d36=0.47(pm/V)(DKDP)
Thermal coefficient dn/dT=7.5×10-6/K(KDP), dn/dT=9.3×10-6/K(DKDP)
Refractive index no=1.4932, ne=1.4599(KDP,1064nm)
Nonlinear Coefficien(pm/v) 0.39(SHG), 0.37(THG)(KDP,1064nm)
Effective SHG coefficient (SHG, THG) 0.16(SHG), 0.08(THG)(KDP,1064nm)
Walk-off Angle  (mrad·cm) 16.6(type I), 28.5(type II)(KDP,1064nm)
Acceptance Angle (mrad·cm) 11.3(type I), 19.2(type II)(KDP,1064nm)
Phase Matching Range (℃m) 275~1200(SHG), 500~2500(THG)(KDP,1064nm)
Temperature Acceptance (℃) 65(KDP,1064nm), 70(DKDP,1064nm)
Damage Threshold(GW/cm2) ~2(SHG), ~0.5(THG)


Potassium dihydrogen



Hot Products

Ask for a quote

*Note: Please be sure to fill in the information accurately and keep the communication open, we will contact you as soon as possible