Crystals Materials
KDP, KD*P (DKDP) Crystal for SHG, THG and SFG applications
  • Wide transparency region
  • Broad Type 1 and Type 2
  • Non-critical phase-matching (NCPM) range
  • Small walk-off angle
  • High damage threshold
  • Wide acceptance angle
  • High optical homogeneity
  • Potassium Dihydrogen Phosphate (KDP crystal) and Potassium Dideuterium Phosphate (KD*P or DKDP crystal) has a high nonlinear coefficient, which allows it to efficiently convert laser radiation to higher frequencies, such as second harmonic generation (SHG), third harmonic generation (THG), and sum-frequency generation (SFG).

    Specifications of KDP, KD*P (DKDP) 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 of KDP crystal
    Chemical Formula KH2PO4
    Transparency Range 200 nm - 1500nm
    Nonlinear Coefficients d36=0.44 pm/V
    Refractive index (@1064 nm) no=1.4938, ne=1.4599
    Electro-optical Coefficients r41=8.8 pm/V; r63=10.3 pm/V
    Longitudinal half-wave voltage Vπ=7.65 KV (λ=546 nm)
    Absorptance 0.07/cm
    Optical damage threshold > 5 GW/cm2
    Physical and chemical properties of D*KDP crystal
    Chemical Formula KD2PO4
    Transparency Range 200 nm - 1600nm
    Nonlinear Coefficients d36=0.40 pm/V
    Refractive index (@1064 nm) no=1.4948, ne=1.4554
    Electro-optical Coefficients r41=8.8 pm/V; r63=25 pm/V
    Longitudinal half-wave voltage Vπ=2.98 KV(λ=546 nm)
    Absorptance 0.006/cm
    Optical damage threshold > 3 GW/cm2

    Stock specification list

    If need other specifications and quantities products, please contact us(
    Part Number Size Theta, θ Phi, φ Coating S1/S2 Application
    KDP-Cry-001 12x12x5 mm 76.5 45 AR@532+266/532+266 nm SHG@532 nm
    KDP-Cry-002 15x15x7 mm 76.5 45 AR@532+266/532+266 nm SHG@532 nm
    DKDP-Cry-001 12x12x20 mm 53.5 0 AR@1064/1064+532 nm SHG@1064 nm
    DKDP-Cry-001 12x12x20 mm 59.5 0 AR@1064+532/355 nm SHG@1064 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.
  • KDP, KD*P (DKDP) Crystal 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 KDP, KD*P (DKDP) Crystal is small.
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