22 May 2019 Description
The chemical formula of Nd: YAP is Nd3+: YAlO3, and the structure is distorted perovskite, belonging to oblique hexagonal crystal system, and spatial group is Pbnm, whose axes a, b and c are perpendicular to each other, belongs to negative uniaxial crystals and is anisotropic. Among the numerous neodymium-doped laser crystals, Nd: YAP crystal not only has high thermal conductivity, but also has a larger excited emission cross section at 4F3/2–4 I13/2 transition. They are one of the most effective laser crystals known at present for the high-power operation at the 1.3 mm, the crystal is mainly pumped by LD. 1.3 mm lasers are widely used in the field of medicine, optical fiber communication and military. What’ s more, water molecule has good absorption at this laser band. Which makes it have a very good hemostatic ability, and widely used in laser therapy, such as hemostasis, neurosurgery, resection of pathological tissues and wrinkle removal. In addition, Nd: YAP crystal has natural birefringence characteristics, which is very beneficial to overcome the thermal depolarization and nonlinear frequency transformation of laser.
Parameter
Material and Specifications
| Materials |
Nd: YAP |
| Orientation |
<5° |
| Parallelism |
≤10″ |
| Perpendicularity |
≤5′ |
| Surface Quality |
10-5 (MIL-O-13830A) |
| Wavefront Distortion |
λ/8 @ 633nm |
| Surface Flatness |
≤ λ/10 @632.8nm |
| Clear Aperture |
>95 % |
| Length tolerance |
+0.5/-0mm |
| Thickness/Diameter Tolerance |
±0.05 mm |
| Damage Threshold |
≥500MW/cm2 |
Physical and Chemical Properties
| Crystal Structure |
orthorhombic – Pbnm |
| Lattice Constants |
a=5,176, b=5,307, c=7,355 |
| Density |
5,35 g/cm3 |
| Melting Point |
1870°C |
| Thermal Conductivity |
0,11 W/(cm K) |
| Thermal Optical Coefficient(dn/dT) |
na:9.7×10-6 K-1 nc:14.5×10-6 K-1 |
| Thermal Expansion/(10-6·K-1@25°C) |
9.5 (a axis), 4.3(b axis), 10.8(c axis) |
| Hardness (Mohs) |
8.5 |
| Shear Modulus /Gpa |
2.2×1012 dyn/cm2 |
| Specific Heat |
400 J/(kg K) |
| Linear dispersion δn/δT [10-6K-1] |
9.7 (na) |
Optical and Spectral Properties
| Laser Transition |
4F3/2→4I9/2 930 nm 4F3/2→4I11/2 1079 nm |
| 4F3/2→4I13/2 1340 nm 4F3/2→4I13/2 1432 nm |
| Laser Wavelength |
930nm 1079nm 1340nm |
| Fluorescence Lifetime |
170ms |
| Refractive index @1064 nm |
na=1,929, nb=1,943, nc=1,952 |
Absorption and Emission Spectrum
 
Emission Cross Section
| Wavelength (nm) |
Emission Cross Section 10-19cm2 |
| a-cut |
b-cut |
c-cut |
| 1079 |
2.05 |
1.76 |
1.38 |
| 1340 |
1.13 |
0.97 |
0.78 |
| |
|
|
|
| 1432 |
|
0.34 |
|
Feature
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