HOME
 

Yb:YAG (Ytterbium Doped Yttrium Aluminum Garnet)

Yb:YAG is one of the most promising laser-active materials and more suitable for diode-pumping than the traditional Nd-doped systems. Compared with the  commonly used Nd:YAG crsytal , Yb:YAG crystal has a much larger absorption bandwidth to reduce thermal management requirements for diode lasers, a longer upper-laser level lifetime, three to four times lower thermal loading per unit pump power. Yb:YAG crystal has the potential to replace Nd:YAG crystal for high power diode-pumped lasers.

Newlight Yb:YAG features

Low fractional heating, less than 11%
High slope efficiency
Broad absorption bands, about 8nm@940nm
No excited-state absorption or up-conversion
Can be conveniently pumped by reliable InGaAs diodes at 940nm(or 970nm)
High thermal conductivity
High optical quality

Basic Properties:

Crystal Structure Cubic
Lattice Parameters 12.01 Å
Melting Point 1970 °C
Moh Hardness 8.5
Density 4.56 g/cm3
Specific Heat 0.59 J/g.cm3
Modulus of Elasticity 310 GPa
Young's Modulus 3.17X104 Kg/mm2
Poisson Ratio 0.3 (est.)
Tensile Strength 0.13~0.26 GPa
Thermal Expansion Coefficient [100]Direction:8.2x10-6/°C (0~250°C )
[110]Direction:7.7x10-6/°C (0~250°C )
[111]Direction:7.8x10-6/°C (0~250°C )
Thermal Conductivity 14W/m/K(@20 °C )
10.5W/m/K(@100 °C )
Thermal Optical Coefficient (dn/dT) 7.3×10-6/°C
Thermal Shock Resistance 790W/m

Optical and Spectral Properties

Dopant concentration Yb: 0.5 ~ 25 at%
Laser Transition 2F5/2 - 2F7/2
Laser Wavelength 1030nm
Photon Energy 1.93×10-19J (@1030nm)
Emission Linewidth 9 nm
Emission Cross Section 2.0×10-20cm2
Fluorescence Lifetime 1.2 μs
Diode Pump Band 940nm or 970nm
Pump Absorption Bandwidth 8 nm
Index of Refraction 1.82
Sellmeier equation
( λ in μm)
n2=2.08745+1.2081 λ2/(λ2-0.02119 )+17.2049 λ2/(λ2-1404.45)
Thermo-Optical Coefficient 9×10-6/ °C
Loss Coefficient 0.003 cm-1

Specifications of finished Yb:YAG crystals

Orientation: axis along <111> or <100> direction
Wavefront Distortion: λ/8 per 25mm @ 633 nm
Extinction Ratio: > 25dB
Dimension Tolerances rods with diameter: ±0.025 mm , Length: ±0.5 mm
Surface Quality: 10/5 Scratch/Dig MIL-O-1380A
Parallelism: <10 arc seconds
Perpendicularity: <5 arc minutes
Clear Aperture: >90%
Surface Flatness: < λ/10 @ 633 nm
Chamfer: <0.1 mm @ 45o
AR Coating Reflectivity  R < 0.25%

 

This site is best viewed with Mozilla Firefox or Google Chrome
Copyright © Newlight Photonics Inc.