Description:
Cr4+:YAG crystals (Chromium Doped Yttrium AIuminum Garnet)
Cr4+:YAG (Y3Al5O12) crystal is ideal for passive Q-switch operation of Nd:YAG and other Nd3+ or Yb3+ doped laser crystals in the wavelength range of 900 nm to 1200 nm. Passive Q-switches or saturable absorbers provide high power laser pulses without electro-optic Q-switches, thereby reducing the package size and eliminating a high voltage power supply. A remarkable feature of Cr4+:YAG is the high damage threshold of >10 J/cm2@1064 nm, 10 ns. Its absorption band extends from 900 nm to 1200 nm and peaks around 1060 nm with a very large absorption cross-section.
Main applications:
- Passively Q-switched lasers for laser rangefinders, LIDAR, and LIBS systems
- Laser systems where short pulses are required
Advantages:
- High chemica stability and reliability
- Easy to operate
- Long lifetime and good thermal conductivity
Basic properties of CrYAG
| Chemical Formula | Cr4+:Y3Al5O12 |
| Crystal Structure | Cubic |
| Mohs Scale of Mineral Hardness | 8.5 |
| Melting Point | 1970 °C |
| Density, g/cm3 | 4.55 |
| Coefficient of Thermal Conductivity @ 25°C, W x cm-1x °K-1 | 0.14 |
| Coefficient of Thermal Expansion | 8.2 x 10-6/ ℃<100> |
| Young’s Modulus | 7.7x 106<100> |
| Thermal Shock Resistance | 790 Wm-1 |
CrYAG specifications:
| Orientation: | <100> or <110> |
| Initial absorption coefficient | 0.1~8.5cm@1064nm |
| Initial transmission | 3%~98% |
| Wavefront Distortion: | λ/8per inch @ 632.8 nm |
| Dimension Tolerances： | rods with diameter: +0.0/-0.05 mm , Length: ±0.1 mm |
| Surface Quality: | 20/10 Scratch/Dig MIL-O-1380A |
| Parallelism: | < 10″ |
| Perpendicularity: | < 10′ |
| Clear Aperture: | > 90% |
| Surface Flatness: | < λ/10 @ 632.8 nm |
| Chamfer: | < 0.1 mm @ 45deg. |
| Size | Upon customer request |
| Coating | AR/HR/PR coating upon customer’s request |
| Damage Threshold | 750MW/CM2 at 1064nm, TEM00, 10ns, 10Hz |
| Quality Warranty Period | One year under proper use |
