Laser Materials Yb:YAG

yb:yag laser material

General Information

Crystals doped with trivalent ytterbium (Yb3+) have demonstrated significant potential for application in compact, efficient, diode-pumped laser systems.[1-4] The Yb3+ ion has only two manifolds, the ground 2F7/2 and the excited 2F5/2 which are separated by approximately 10,000 cm-1. As a result, Yb3+doped materials have spectroscopic and laser properties that are advantageous for high energy 1 µm laser systems. In particular, Yb3+ doped materials should not suffer from concentration quenching, upconversion, or excited state absorption. The Yb3+ ion also has a long energy storage lifetime (typically three to four times that of Nd3+ in the same host) and a very small quantum defect which reduces heat generation during lasing.

In the specific case of the host material YAG, Yb3+ has a storage lifetime of 950 µs and a quantum defect of only 8.6%. Yb3+:YAG also has a broad pump line at 940 nm that is 10 times broader than the 808 nm pump line in Nd3+YAG making the system less sensitive to thermal drift of the pump diodes wavelength. These material properties combined with the development of robust long-lifetime InGaAs pump diodes at 940 nm have made this material a superior candidate for diode-pumped high-energy lasers.

Laser systems based on SMC's UP-grade Yb3+:YAG have been reported with cw output powers exceeding 430 W,[1] quasi-cw output powers of 600 W,[4] and optical to optical efficiencies of 60%.[2] Such systems have been reported to be scaleable with output powers at the kW level.

Crystals of Yb3+ doped YAG are available in a variety of dopant concentrations from 1% - 100% (e.g. Ytterbium aluminum garnet - YbAG).

Please contact us with your specific requirements or for availability and pricing of currently stocked compositions.

Dopant Ion

Yb3+ Concentration Range 1.0 - 100 atomic %
Dopant Ion Density @ 1 atomic %
Y3+ Site 1.38 x 1020 cm-3
Al3+Site (IV) 1.38 x 1022 cm-3
Al3+Site (VI) 0.92 x 1022 cm-3

Common Operating Specs

Emission Wavelength 1.064 μm
Laser Transition 2F5/24F7/2
Intrinsic Flouresence Lifetime (≤ 15 atomic % Yb doping) 967 μs
Pump Wavelength 941 nm

Physical Properties

Coefficient of Thermal Expansion 6.14 x 10-6 K-1
Thermal Diffusivity 0.041 cm2 s-2
Thermal Conductivity 11.2 W m-1 K-1
Specific Heat (Cp) 0.59 J g-1 K-1
Thermal Shock Resistant 800 W m-1
Refractive Index @ 632.8 nm 1.83
dn/dT (Thermal Coefficient of Refractive Index) @ 1064nm 7.8 10-6 K-1
Molecular Weight 593.7 g mol-1
Melting Point 1965°C
Density 4.56 g cm-3
MOHS Hardness 8.25
Young’s Modulus 335 Gpa
Tensile Strength 2 Gpa
Crystal Structure 8Cubic
Standard Orientation <111>
Y3+ Site Symmetry D2
Lattice Constant a=12.013 Å

References

1) Camille Bibeau and Ray Beach, “CW and Q-switched performance of a diode end-pumped Yb:YAG laser,” Advanced Solid-State Lasers, January 27-29, 1997 Orlando, FL.

2) M. Karszewski, U. Brauch, A. Giesen, I. Johannsen, U. Schiegg, C. Stewen, A. Voss, “Advanced Tunability and High-Power TEM00-Operation of the Yb:YAG Thin Disc Laser,” Advanced Solid-State Lasers, January 27-29, 1997 Orlando, FL.

3) H. Bruesselbach and D. Sumida, “69-W-average power Yb:YAG laser,” Opt. Lett. 21, 480 (1996).

4) H. Bruesselback, D. S. Sumida, R. Reeder, and R. W. Byren, “High-Power Side-Diode-Pumped Yb:YAG Laser,” Advanced Solid-State Lasers, January 27-29, 1997
Orlando, FL.

Absorption Coefficient Chart

yb:yag chart

Data Sheet Downloads



pdf Yb:YAG Data Sheet