Chromium Doped Yttrium Aluminum Garnet (Cr4+:YAG)
Cr4+:YAG (Y3Al5O12) is an excellent crystal for passively Q-switching diode pumped or lamp-pumped Nd:YAG, Nd:YLF, Nd:YVO4 or other Nd and Yb doped lasers at wavelength from 0.8 to 1.2 um. Because of its high damage threshold (> 500 MW/cm2) and being easy to be operated, it will replace LiF and Dye which are commonly used as passive Q-switching materials.
Basic Properties of Cr 4+ :YAG
| Chemical Formula |
Cr4+:Y3Al5O12 |
| Crystal Structure |
Cubic garnet |
| Recovery time |
8.5 μs |
| Hardness |
8.5 Mohs |
| Density |
4.56 g/cm3 |
| Thermal conductivity |
12.13 W/m/K |
| Refractive index |
1.82 @ 1064nm |
| Ground state absorption cross section |
σs1=4.3x10-18cm2 |
| Excited state absorption cross section |
σs2=8.2x10-19cm2 |
| Fluorescence lifetime |
3.4 μs |
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We provides Cr 4+ :YAG with Cr4+ doping level from 0.5 mol% to 3 mol%. The size could be from 2x2 mm2 to 12x12 mm2 with length from 0.1 mm to 12 mm. AR-coatings and HR-coatings are also available. We can control the transmission from 1% to 99% according to customers' requirements.
For Cr4+:YAG, the pulse width of passively Q-switched lasers could be as short as 5ns for diode pumped Nd:YAG lasers and repetition as high as 10kHz for diode pumped Nd:YVO4 lasers. Furthermore, an efficient green output at 532nm, and UV output at 355nm and 266nm were generated, after a subsequent intra-cavity SHG in KTP or LBO, THG in LBO or BBO and 4HG in BBO for diode pumped, passive Q-switched Nd:YAG and Nd:YVO4 lasers.
Cr4+:YAG is also a laser crystal with tunable output from 1.35 mm to 1.6 mm. It can generate ultrashort pulse laser (to femto-second pulsed) when pumped by Nd:YAG laser at 1.064 mm.
Cr4+:YAG crystal has been demonstrated as a Self-Pumped Phase- conjugate Mirror in a Nanosecond Nd:YAG high power loop resonator. It compensates not only for phase aberrations, but also for polarization aberrations induced into the loop resonator.
Specification
| Orientation: |
The rod axis is along [100] |
| Cr4+ concentration: |
0.5 mol% ~ 3 mol% |
| Aperture |
2x2 ~ 14x14 mm |
| Length: |
0.1 ~ 12 mm |
| Initial transmission: |
5% ~ 99% |
| Angle tolerance: |
Δθ< ± 0.5°; Δφ< ±0.5° |
| Flatness: |
l /8 @ 633 nm |
| Parallelism: |
20 arc sec |
| Perpendicularity: |
5 arc minutes |
| Surface finishing: |
20/10 scratch/dig to MIL-O-13830A |
| Wavefront distortion: |
less than λ/8 @ 633 nm |
Anti-Reflection (AR) Coating
AR coatings are available upon request @ 1064nm, 1053nm , or other wavelengths. The typical reflectance is R < 0.20% per surface.
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