Neodymium-doped yttrium lithium fluoride (Nd:YLF) crystals are one of the most commonly used solid-state laser elements because of their long fluorescence decay time at room temperature, weak thermal lensing effect, and natural birefringence. The most common Nd:YLF lasers to date operate at 1047 nm (π-polarized) and 1053 nm (σ-polarized) because of the higher intensity.
Alfa Chemistry is a professional customizer of laser crystals. We will guide customers patiently and meticulously to complete the online customization process ofNd:YLF laser crystals. We grow Nd:YLF laser crystals via the Czochralski method.
Advantages of Nd:YLF Crystals
The Nd:YLF crystals are characterized by long lifetime of 4F3/2 Nd energy levels. The lower thermal conductivity and the weaker negative dn/dT result in lower thermal distortion and better output beam quality compared to Nd:YAG. Another distinguishing feature is the high UV transparency, which facilitates pumping with xenon flash lamps.
Fig 1. Partial energy level diagram of Nd:YLF crystal. (Turri G, et al. 2021)
Advantages:
- High power, low beam divergence angle, efficient single-mode operation
- High average power Q tuning with medium repetition rate
- Potential uniform mode for large diameter rods or plates
- Excited emission cross section favors low CW threshold
- 1053nm output of Nd:YLF matches the gain curve of Nd:Glass
Properties of Nd:YLF Crystals
| Physical Properties | |
|---|---|
| Crystal Structure | Tetragonal |
| Lattice Parameter | a=5.16 Å, c=10.85 Å |
| Density | 3.99 g/cm3 |
| Melting Point | 819 ℃ |
| Mohs Hardness | 4 ~ 5 |
| Thermal Conductivity | 0.063 /K<111> |
| Thermal Expansion Coefficients | 8.3×10-6/k∥c; 13.3×10-6/ k⊥c |
| Specific Heat | 0.79 J/g/K |
| dn/dT | -4.6×10-6 (||c) K-1, -6.6×10-6 (||a) K-1 |
| Optical Properties | |
| Transparency Range | 180 ~ 6700nm |
| Peak Absorption Coefficient | (for 1.2% Nd) α= 10.8cm-1 (792.0 nm E∥c); α= 3.59cm-1 (797.0 nm E⊥c) |
| Absorption Peak Wavelength | 792 nm |
| Peak Stimulated Emission Cross Section | 1.8×10-19/cm2(E∥c) at 1047nm; 1.2×10-19/cm2(E⊥c) at 1053nm |
| Absorption Bandwidth at Peak Wavelength | ~5 nm |
| Spontaneous Fluorescence Lifetime | 485 µs for 1% Nd doping |
| Laser Wavelength | 1047nm (∥c, a-cut crystal); 1053nm(⊥c, a or c-cut crystal) |
| Scatter Losses | <0.2%/cm |
| Alfa Chemistry offers Nd:YLF specification | |
| Dimension | Upon customer request |
| Dimension Tolerance | Rods with diameter +0.0/-0.05 mm, L±0.1mm |
| Doping(atm%) | 0.01% ~ 3% |
| Orientation | A-cut or C-cut |
| Flatness | λ/10 @ 632.8nm |
| Surface Quality | 10/5 Scratch/Dig MIL-O-1380A |
| Clear Aperture | > 90% |
| Damage Threshold | 750MW/cm2 at 1064nm, TEM00, 10ns, 10Hz |
| Coating | AR/HR/PR coating upon customer's request |
| Quality Warranty Period | One year under proper use |
Why Choose Alfa Chemistry?
Alfa Chemistry sells cutting-edge Nd:YAG laser crystals to customers. According to customer needs, dimensions are customized. We apply the CZ growth method to the growth of YLF-based crystals. Each crystal is grown from high-quality starting materials, and its performance is ensured by bulk ingot interferometry, a He-Ne laser for accurate inspection of scattered particles in crystals, and a spectrophotometer for accurate volume loss measurement.
If you need technical advice, please contact our technical team to learn more about our high-quality services.
Reference
- Turri G, et al. (2021). "Temperature-Dependent Stimulated Emission Cross-Section in Nd3+:YLF Crystal." Materials. 14(2): 431.