Passive Q-Switching is preferred for simplicity of manufacturing and operation, low cost, and reduced system size and weight. Cr4+: YAG (Y3Al5O12) crystals are excellent for passive Q-Switching diode pumped or lamp-pumped Nd: YAG, Nd: YLF, Yb: YAG or other Nd and Yb doped lasers at wavelengths from 1.0 to 1.2mm. Because they are chemically stable, durable, UV resistant, have good thermal conductivity, have a high damage threshold (>500mW/cm2) and ease of operation, they will replace traditional materials such as LiF, organic dye and color centers.
| Formula | Cr4: Y3AI5O12 |
|---|---|
| Crystal Structure | Cubic Garnet |
| Dopant Level | 0.03 mol% - 0.05 mol% |
| Hardness | 8.5 (Mohs) |
| Damage Threshold | >500MW/cm2 |
| Refractive Index | 1.82 @1064nm |
| ATTRIBUTE | COMMERCIAL | HIGH PRECISION |
|---|---|---|
| Flatness | λ/4 | λ/10 |
| Wavefront Distortion | λ/4 | λ/10 |
| Surface Quality | 20-10 scratch and dig | 10-5 scratch and dig |
AR coatings and HR coatings are also available. The initial transmission (To) can be controlled from 10% to 95% according to customer requirements. Standard size Cr4+:YAG crystals of 3x3mm2 with To=80% or 90% are in stock and available for immediate delivery.
Preliminary experiments done on Casix\'s Cr:YAG crystals show that the pulse width of passively Q-switched lasers can be as short as 9ns for diode pumped Nd:YAG lasers with repetition as high as 10kHz for diode pumped Nd:YVO4 lasers. Furthermore, an efficient green output @532nm and UV output@355nm and 266nm were generated after a subsequent intra-cavity SHG in KTP for diode pumped and passive Q-switched Nd:YAG and Nd:YVO4 lasers.
Cr:YAG is also a laser crystal with tunable output from 1.35um to 1.6um. It can generate ultrashort pulse lasers (to fs pulsed) when pumped by Nd:YAG lasers at 1.064um.