Ho:YAG Laser Crystal

22 May 2019

Description

The radiation wavelength of Ho3+ ions is near 2100nm, which is located in the human eye safe band and has a high transmittance in the atmosphere, and has important application prospect in the fields of remote sensing detection, laser ranging and laser radar, etc.. Meanwhile, 2100nm locates in the absorption peak of water molecule, which is highly absorbed by human tissues. When Ho laser is used for medical surgery, its penetration depth in the human body is only a few tens of micrometers, and it has little heat damage to the surrounding tissues of the human body. Therefore, it is widely used in medical surgery and treatment. Ho laser can also be used as pump source, through the non-linear effect of crystal (such as ZGP crystal), infrared laser with wavelength of 3 ~ 5 mm can be realized.

Parameter

Material and Specifications

Materials	Ho: YAG
Concentration Tolerance (atm%)	0.2% ~3%(as per customers request)
Orientation	crystalline direction
Parallelism	<10”
Perpendicularity	<5”
Surface Quality	10/5 Scratch/dig per MIL-O-1380A
Wavefront Distortion	λ/8per inch @633nm
Surface Flatness	λ/10@ 633 nm
Clear Aperture	>90
Thickness/Diameter Tolerance	Rods with diameter:(+0、-0.05)mm,( ±0.5) mm

Physical and Chemical Properties

Crystal Structure	Cubic
Lattice Constants	12.01Å
Density	4.56g/cm³
Melting Point	1970°C
Thermal Conductivity	14W/m/K, 20°C; 10.5W/m/K, 100°C
Thermal Shock Resistance	790W/m
Thermal Optical Coefficient(d_n/d_T)	7.3×10^-6/ K
Thermal Expansion /（10^-6·K^-1@25°C ）	[100]:8.2×10^-6/K@ 0~250℃; [110]:7.7×10^-6/K@0~250℃;
Thermal Expansion /（10^-6·K^-1@25°C ）	[111]: 7.8×10^-6/K@0~250℃
Hardness (Mohs)	8.5
Young`s Modulus /GPa	3.17×10⁴Kg/mm²
Shear Modulus /Gpa	310GPa
Extinction Ratio	>28dB
Specific Heat	0.59J/g.cm³@0-20℃
Solubility	Insoluble in water, slightly soluble in ordinary acids
Poisson Ratio	0.3

Optical and Spectral Properties

Laser Transition	⁵I₇→⁵I₈
Laser Wavelength	2.05μm
Effective Stimulated Absorption Cross Section	1.09×10^-20cm²
Effectively Stimulated Emission Cross Section	1.14×10^-20cm²
Pump Wavelength	1908 nm
Laser Wavelength	2090 nm
Fluorescence Lifetime	7 ms
quantum Efficiency	1
Refractive Index @1.030 μm	1.82
Upper Conversion Loss Factor	1.8, 2.6, 5.3×10^-18cm³/s