Co:Spinel Crystals

  • Orientation Tolerence: < 0.5°
  • Thickness/Diameter Tolerance: ±0.05 mm
  • Surface Flatness: <λ/8@632 nm
  • Wavefront Distortion: <λ/4@632 nm
  • Surface Quality: 10/5
  • Parallel: 10〞
  • Perpendicular:
  • Clear Aperture: >90%
  • Chamfer: <0.1×45°
  • Maximum dimensions: Dia(3-15)×(3-50)mm
  • Product Detail


    Test report

    Passive Q-switches or saturable absorbers generate high power laser pulses without the use of electro-optic Q-switches, thereby reducing the package size and eliminating a high voltage power supply. Co2+:MgAl2O4 is a relatively new material for passive Q-switching in lasers emitting from 1.2 to 1.6μm, in particular, for eye-safe 1.54μm Er:glass laser, but also works at 1.44μm and 1.34μm laser wavelengths. Spinel is a hard, stable crystal that polishes well. Cobalt substitutes readily for magnesium in the Spinel host without the need for additional charge compensation ions. High absorption cross section (3.5×10-19 cm2) permits Q-switching of Er:glass laser without intracavity focusing both with flash-lamp and diode laser pumping. Negligible excited-state absorption results in high contrast ratio of Q-switch, i.e. the ratio of initial (small signal) to saturated absorption is higher than 10.

    •  Suitable for 1540 nm eye-safe lasers
    •  High absorption section
    •  Negligible excited state absorption
    •  High optical quality
    •  Uniformly distributed Co

    •  Eye-safe 1540 nm Er:glass laser
    •  1440 nm laser
    •  1340 nm laser
    •  Eye-safe laser range finder

    Chemical formula Co2+:MgAl2O4
    Crystal structure Cubic
    Lattice parameters 8.07Å
    Density 3.62 g/cm3
    Melting Point 2105°C
    Refractive Index n=1.6948 @1.54 µm
    Thermal Conductivity /(W·cm-1·K-1@25°C) 0.033W
    Specific Heat/ (J·g-1·K-1) 1.046
    Thermal Expansion /(10-6 /°C@25°C ) 5.9
    Hardness (Mohs) 8.2
    Extinction Ratio 25dB
    Orientation [100] or [111] < ±0.5°
    Optical density 0.1-0.9
    Damage Threshold >500 MW/cm2
    Doping concentration of Co2+ 0.01-0.3 atm%
    Absorption coefficient 0 ~ 7 cm-1
    Working wavelength 1200 – 1600 nm
    Coatings AR/AR@1540,R<0.2%; AR/AR@1340,R<0.2%
    Orientation Tolerence < 0.5°
    Thickness/Diameter Tolerance ±0.05 mm
    Surface Flatness <λ/8@632 nm
    Wavefront Distortion <λ/4@632 nm
    Surface Quality 10/5
    Parallel 10
    Clear Aperture >90%
    Chamfer <0.1×45°
    Maximum dimensions Dia(3-15)×(3-50)mm

    Spinel01 Spinel02 Spinel03