Yb:YVO4, Ytterbium-doped Yttrium Orthovanadate, is a crystalline solid used as an active laser-gain medium。It is an excellent working crystal material for solid-state laser and more suitable for diode-pumped systems than traditional Nd-doped systems.
Compared with the commonly used Nd:YVO4 crystal, Yb:YVO4 crystal has a wider absorption bandwidth, which can reduce the temperature management requirements in the use of diode lasers, longer laser upper energy level life, and 3-4 times lower thermal load per unit of pump power.Yb:YVO4 crystal can well replace the use of Nd:YVO4 crystal at 1064nm, and its second harmonic at 515nm has the same function of the Ar ion laser emitting 514nm wavelength.
Application of Yb:YVO4 examples
- High power CW, Q-switched and mode-locked lasers
- Thin-disk lasers
Photonchina Yb:YVO4 Crystal Basic Properties
|Crystal Structure||Tetragonal, D4h -l41/amd|
|Segregation coefficient of Yb3+||0.96|
|Mohs Hardness||5 glass-like|
|Thermal expansion Coefficient(300K)||aa=4.43*10-6 /K, ac=11.37*10-6 /K|
|Thermal optical coefficient(300K)||dno /dT=8.5×10-6 /K; dne /dT=2.9×10-6 /K|
|Thermal Conductivity Coefficient(300K)||||C: 5.23 w/m/k; ⊥C:5.10w/m/k|
|Emission linewidth(4.8% Yb)||31nm|
|Emission cross section(4.8% Yb)||0.6 x10-20 cm2 @1030nm|
|Fluorescence lifetime(4.8% Yb)||1.1ms|
Features of Yb3+-doped laser crystal:
1) High light conversion efficiency;
2) The simple electronic structure excludes excited-state absorption. Its electronic configuration is [Xe] 4f13. There is only one ground state 2F7 / 2 and one excited state 2F5 / 2. The energy level interval between them is about 10000 cm-1.Under the action of the crystal field, the energy level produces Stark splitting, forming a quasi-three-level laser operating mechanism;
3) Yb3+ can be doped with high concentration (the atomic fraction of Yb3+ in Yb:YVO4 crystal can be as high as 10% or more) and there will be no concentration quenching phenomenon;
4) Since the pump energy level is close to the upper energy level of the laser, the thermal load in the material caused by non-radiative relaxation is low, which is only 1/3 of the same laser material doped with Nd3+;
5) The absorption wavelength range of Yb3+ is 0.9-1.1 μm, which can be effectively coupled with the InGaAs LD pump source. The absorption line width (FWHM) is large, and the matching pump wavelength can be obtained without strict temperature control.
6) The fluorescence lifetime is longer, which is about three times that of the same Nd3+-doped laser material, it therefore is beneficial to energy storage;
7) The quantum defect is low, and the pump wavelength is very close to the laser output wavelength, which will result in a large intrinsic laser slope efficiency, and the quantum efficiency can theoretically reach 90%.
8) Custom crystals available upon request.
It can be seen from the above characteristics that the LD-pumped Yb3+ laser will be significantly better than the Nd3+ laser in some applications. Thanks to the availability of high-concentration doping of Yb3+ ions, the gain medium in Yb3+-doped laser materials can also be made into microchips. This is of great importance for realizing the integration and miniaturization of LD-pumped solid-state lasers.
Photonchina can provide Yb:YVO4 crystals with different doping concentrations according to customer needs, and already has the capacity for mass production.