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〞 |
Perpendicular | 5ˊ |
Clear Aperture | >90% |
Chamfer | <0.1×45° |
Maximum dimensions | Dia(3-15)×(3-50)mm |