RZT

Nd:YVO₄ is one of the most efficient solid-state laser host crystal at present. Its large stimulated emission cross-section at laser wavelength, high absorption coefficient and wide absorption bandwidth at pump wavelength, high laser induced damage threshold as well as good physical, optical and mechanical properties make Nd:YVO₄ an excellent crystal for the high power , stable and cost-effective diode laser-pumped solid-state lasers. With the design of Nd:YVO₄ + frequency crystal KTP, man can produce tiny all solid-state green lasers. Nd:YVO₄ lasers have been applied in many areas of military affairs, information industry, etc.

Nd:YVO₄ is the most efficient laser host crystal for diode pumping among the current commercial laser crystals, especially, for low to middle power density.

This is mainly for its absorption and emission features surpassing Nd:YAG. Pumped by laser diodes, Nd:YVO₄ crystal has been incorporated with high NLO coefficient crystals (LBO,BBO,or KPT) to frequency-shift the output from the near infrared to green, blue, or even UV. This incorporation to construct all solid state lasers is an ideal laser tool that can cover the most widespread applications of lasers, including machining, material processing, spectroscopy, wafer inspection, light displays, medical diagnostics, laser printing, and data storage, etc. It has been shown that Nd:YVO₄ based diode pumped solid state lasers are rapidly occupying the markets traditionally dominated by water-cooled ion lasers and lamp-pumped lasers, especially when compact design and single-longitudinal-mode outputs are required.

possess the advantages of lower dependency on pump wavelength and temperature control of a diode laser, wide absorption band, higher slope efficiency, lower lasing threshold, linearly polarized emission and single-mode output. For the applications in which more compact design and the single-longitudinal-mode output are needed, Nd:YVO₄ shows its particular advantages over other commonly used laser crystals. The diode laser-pumped Nd:YVO₄ compact laser and its frequency-doubled green, red or bule laser will be the ideal laser tools of machining, material processing, spectroscopy, wafer inspection, light show, medical diagnostics, laser printing and the most

Atomic Density	~1.37 x 10 20 atoms / cm3
Crystal Structure	Zircon Tetragonal, space group D4h, a=b=7.12, c= 6.29
Density	4.22g / cm3
Mohs Hardness	Glass-like, ~5
Thermal Expansion Coefficient	aa=4.43 x 10-6 / K, ac=11.37 x 10-6 / K
Crystal class	positive uniaxial, no=na=nb, ne=nc, no=1.9573, ne=2.1652, @ 1064nm no=1.9721, ne=2.1858, @ 808nm no=2.0210, ne=2.2560, @ 532nm
Sellmeier Equation (for pure YVO4 crystals): no2=3.77834+0.069736/(2 - 0.04724) - 0.0108133.2 ne2=4.59905+0.110534/(2 - 0.04813) - 0.0122676.2
Absorption Length	0.32 mm @ 808 nm
Intrinsic Loss	Less 0.1% cm-1 , @1064 nm

Nd:YVO₄ shows high absorption coefficients at pumping wavelengths. Therefore, a crystal short-in-length (e.g. 1mm) is preferred, and more compact lasers can be constructed by using Nd:YVO₄ than using Nd:YAG. Furthermore, it has a wide and smoothly-varied bandwidth of absorption, so that it allows of less stringent requirements of diode laser selection and wavelength control as compared with Nd:YAG. Different doping levels Nd:YVO₄ are shown showed as follow

Normalized fluorescence spectra from 800 nm to 1600 nm of Nd 1.1 at. % doped Nd:YVO₄ for p polarization (a) and for s porlarization (b).

Nd: Dopant Level	0.05 - 3.0 atm%
Standard Dimensions	3x3x1-8 mm3, 4x4x4-12 mm3 Dia.2-5mm rods
Wavefront Distortion	< /8 at 633 nm
Scattering Sites	invisible, probed with a He-Ne laser
Orientation	+/-0.5 deg
Dimensional Tolerance	+0.1/-0.1 mm
End-faces Configuration	Plano/plano, plano/Brewster, Brewster/Brewster
Surface quality	10/5 Scratch/Dig per MIL-O-13830B
Flatness	/10 at 633 nm
Clear Aperture	> Central 90%
Parallelism	< 10 arc sec.
Intrinsic Loss	< 0.1% cm-1