Description
Introduction
Neodymium Doped Yttrium Aluminum Garnet (Nd:YAG) is the earliest and most famous laser host crystal. Since it combines great advantages in many basic properties, Nd:YAG is the ubiquitous presence for near-infrared solid-state lasers and their frequency-doubler, tripler, and higher order multiplier.
- High gain
- Low threshold
- High efficiency
- Low loss at 1.06 µm
- Good thermal conductivity and thermal shock characteristics
- Mechanical strength
- high optical quality
- Material characteristics that allow for various modes of operation (CW, pulsed, Q-switched, mode locked)
Table 1. Basic Properties
| Crystal Structure | Cubic |
| Lattice Parameter | 12.01 Å |
| Density | 4.5 g/cm3 |
| Melting Point | 1970℃ |
| Reflective Index | 1.82 |
| Mohs Hardness | 8.5 Mohs |
| Thermal Expansion Coefficient | 7.8×10-6 /K <111＞, 0-250℃ |
| Thermal Conductivity | 14 W/m/K, 20℃
10.5 W/m/K, 100℃ |
| Stimulated Emission Cross-section | 2.8 × 10-19 cm-2 |
| Relaxation Time of Terminal Lasing Level | 30 ns |
| Fluorescent Lifetime | 550 µs |
| Spontaneous Fluorescence | 230 µs |
| Linewidth | 0.6 nm |
| Loss Coefficient | 0.003 cm-1 @1064 nm |
Specifications of Nd:YAG crystal
Table 2. Specifications
| Dopant Concentration | Nd: 0.3~2.0 (± 0.1) at.% |
| Dimension | size up to dia. 15 × 180 mm and maximum diameter of dia. 40 mm × 2 mm |
| Dimensional Tolerances | Diameter: ±0.1mm
Length: ±0.5 mm |
| Surface Quality (Scratch/Dig) | 10/5 to MIL-PRF-13830B |
| Wavefront Distortion | λ/8 @633 nm |
| Flatness | λ/8 @633 nm |
| Parallelism | 20 arc sec |
| Perpendicularity | ≦15 arc min |
| Chamfer | ≦0.2 mm×45° |
| HR Coating | R＞99.8% @1064 nm, R<5% @808 nm |
| Other HR Coatings, such as HR-1064/532 nm, HR-946 nm, HR-1319 nm and other wavelengths are available. | |
| Damage Threshold | ＞500 MW/cm2 @1064 nm, 10 ns, 10 Hz (AR-coated) |
Table 3. Optical Parameter of Nd:YAG crystal
| Diameter (mm) | Standard grade | Excellent grade | Super-excellent grade |
| Φ3-6.35 | ≦ 0.5 fringes/inch | ≦ 0.25 fringes/inch | ≦ 0.1 fringes/inch |
| ≧ 25 dB | ≧ 28 dB | ≧ 30 dB | |
| Φ7-10 | ≦ 0.7 fringes/inch | ≦ 0.4 fringes/inch | ≦ 0.16 fringes/inch |
| ≧ 22 dB | ≧ 25 dB | ≧ 28 dB | |
| Φ11-13 | ≦ 1 fringes/inch | ≦ 0.6 fringes/inch | ≦ 0.2 fringes/inch |
| ≧ 20 dB | ≧ 23 dB | ≧ 26 dB | |
| Φ14-16 | ≦ 1.2 fringes/inch | ≦ 0.8 fringes/inch | ≦ 0.25 fringes/inch |
| ≧ 18 dB | ≧ 20 dB | ≧ 23 dB |
Higher grade or specific Nd:YAG rods or slabs, and Nd:YAG rods for 946 nm and 1319 nm lasers can be provided. Er:YAG, Yb:YAG and other ion doped YAG crystals are also available upon request.
