Undoped YVO4 is an excellent birefringence optical crystal developed newly. It has very good transmission in a wide wavelength range from visible to infrared, large index of refractivity and birefringence difference. Compared with other important birefringence crystals, YVO4 has higher hardness, better fabrication property, water insoluble and man-made than calcite (CaCO3 single crystal); easier to get large, high quality crystal and lower cost than rutile (TiO2 single crystal). Those outstanding properties make YVO4 very important birefringence optical material and widely used in opto-electronic research, development and industry. For example, the optical communication system needs a huge quantity devices of undoped YVO4, such as fible optical isolators, circulators, beam displacers, Glan polarizers and other polarizing devices.

Specifications:

Crystal Structure	Zirconium Tetragonal
Space Group	D4h
Lattice Constant	a=b=7.12 Å, c=6.29 Å
Crystal Class	Positive Uniaxial, na= nb= no, nc= ne
Atomic Density	~1.37x1020atoms/cm3
Growth Method	Czokralski
Melting Point	1825°C
Density	4.22 g/cm3
Mohs hardness	~5 (like glass)
Thermal Expansion	aa=4.43x10-6/K ac=11.37x1010-6/K
Thermal Conductivity	//C: 0.0523W.cm/K   ⊥C: 0.0510W.cm/K
Transmission Range	0.45—5µm
Sellmeier equation (λ: μm)	no2 =3.77843+0.069736/(λ2-0.04724)-0.0108133λ2 ne2 =4.55905+0.110534/(λ2 -0.04813)-0.0122676λ2
n \ Wavelength	0.63µm	1.30µm	1.55µm
Index of refractivity no	1.9929	1.9500	1.9447
Index of refractivity ne	2.22154	2.1554	2.1486
Birefringency Differency (△n=ne-no)	0.2225	0.2054	0.2039
Opticlal axisρ 45°	6.04°	5.72°	5.69°
Thermal Optical Coefficient	dna/dt=8.5x10-6/K,  dnc/dt=3.0x10-6/K