Co2+:MgAl2O4 crystal
Co2+:MgAl2O4 is a relatively new material for passive Q-switching in lasers emitting from 1.2 to 1.6 μm, in particular, for eye-safe 1.54 μm Er:glass laser, but also works at 1.44 μm and 1.34 μm 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 of Q-switch, i.e. the ratio of initial (small signal) to saturated absorption is higher than 10.
• Negligible excited-state absorption；
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Attributes
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value
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Chemical Formula
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Co2+:MgAl2O4
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Crystal Structure
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cube
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Lattice Constant
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8.07Å
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Density
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3.62 g/cm3
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Melting Point
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2105℃
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Reflective Index
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n=1.6948 @1.54μm
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Stimulated Emission Cross Section
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0.033W
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Specific heat capacity/(J•g-1•K-1)
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1.046
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Thermal expansion coefficient/（10-6/℃ @25℃）
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5.9
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Mohs hardness
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8.2 |
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Extinction Ratio
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25dB
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Lattice orientation
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[100] or [111] < ±0.5°
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Optical density
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0.1-0.9
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Damage threshold
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>500 MW/cm2
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Co2+ doping concentration
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0.01-0.3 atm%
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