Crystals Materials
KGW Crystals for raman shifter for nanosecond applications
  • Broad transparency range from 300 nm to 5 μm
  • Two pump polarization-dependent Raman shifts at 768 cm-1 and 901 cm-1
  • Excellent Raman shifter for picosecond applications
  • Surface Quality: 10/5 Scratch/Dig MIL-O-1380A
  • Parallelism: < 10″
  • Perpendicularity: < 5'
  • Clear Aperture: > 90%
  • Surface Flatness: < λ/10 @ 632.8 nm
  • Coating: AR/HR/PR coating upon customer's request
  • Quality Warranty Period: One year
  • Potassium gadolinium tungstate (KGd(WO4)2, KGW) crystals feature good mechanical properties, relatively good thermal conductivity (2,5-3,4 Wm-1K-1), and a wide transparency range, which spans from 350 nm to 5 µm. KGW as a Raman crystal features two large Raman modes at 768 cm-1 and 901 cm-1, which are pump polarization dependent.

    Specifications of KGW Crystal
    Orientation b-cut
    Clear aperture >90%
    Face dimensions tolerance +0.0/-0.1 mm
    Length tolerance ±0.1 mm
    Parallelism error <20 arcsec
    Perpendicularity error <10 arcmin
    Protective chamfers <0.1 mm at 45˚
    Surface quality 10-5 S-D
    Surface flatness <λ/8@632.8 nm
    Wavefront distortion <λ/4@632.8 nm
    Coatings AR(R<0.7%)@500-650 nm
    Laser-induced damage threshold >10 J/cm2@1064 nm, 10 ns
    Mount Unmounted
    Physical and optical properties
    Property Value
    Chemical formula KGd(WO4)2
    Crystal structure Monoclinic, C2c
    Lattice parameters a = 10.652(4) Å, b = 10.374(6) Å, c = 7.582(2) Å
    Density 7.27 g/cm3
    Mohs hardness 4-5
    Transparency range 0.3-5 μm
    Refractive indices @1064 nm np=1.982, nm=2.010, ng=2.061
    Thermal conductivity Ka = 2.6 Wm-1K-1, Kb = 3.8 Wm-1K-1, Kc = 3.4 Wm-1K-1
    dn/dT dnp/dT = -15.7 × 10-6K-1, dnm/dT = -11.8 × 10-6K-1, dng/dT = -17.3 × 10-6K-1
    Raman frequency shift 901 cm-1 (p[mm]p), 767 cm-1 (p[gg]p)
    Raman linewidth 5.4 cm-1@901 cm-1 (p[mm]p), 6.4 cm-1@767 cm-1 (p[gg]p)
    Raman gain (ps, transient-state regime) 11 cm/GW@532 nm, 3 cm/GW@1064 nm
    Dephasing time 2 ps

    Stock specification list

    If need other specifications and quantities products, please contact us(
    Part Number Face size Length Doping Coating
    KGW-Cry-001 5.0*5.0 mm 15.0 mm undoped UnCoated
    KGW-Cry-002 5.0*5.0 mm 50.0 mm undoped AR/AR@450-800 nm


  • Anti-reflection coatings are available at your specified wavelength.
  • Be sure to wear laser safety goggles when checking optical path and adjusting optical axis.
  • To inquiry or order a finished KGW laser rod, please specify the specification listed above, for common application, we only need to know the main specification: Nd-dopant concentration, sizes, and coating. For special request, please specify specification in details for evaluation and fabrication.
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