YVO4

YVO4


The yttrium orthovanadate (YVO4) is a positive uniaxial crystal grown with Czochralski method. It has good mechanical and physical properties and is ideal for optical polarizing components because of its wide transparency range and large birefringence. It also has good physical and favorable mechanical properties than other birefringent other crystals, which make it well suited for compact fiber optical components, such as isolators, circulators and interleavers etc.

 Comparison of basic properties between YVO4 and Other Birefringent Crystals

  YVO4  TiO2  CaCO3  LiNbO3 
Thermal Expansion ( /°C) c-axis  11.4x10-6  9.2x10-6  26.3x10-6  16.7x10-6 
a-axis  4.4x10-6  7.1x10-6  5.4x10-6  7x10-6 
Refractive Index  n 1.9447@1550nm  2.454@1530nm  1.6346@ 1497nm  2.2151@ 1440nm 
n 2.1486@1550nm  2.710@1530nm  1.4774@ 1497nm  2.1413@ 1440nm 
Birefringence(ne-no)  0.2039@1550nm  0.256@1530nm  -0.1572@ 1497nm  -0.0738@ 1440nm 
Mohs Hardness  5 6.5 3 5
Deliquescence  None  None  Weak  None 
Transparency range  0.4-5mm  0.4-5mm  0.35-2.3mm  0.4-5mm 

Basic Properties

Transparency Range High transmittance from 0.4 to 5mm
Crystal Symmetry Zircon Tetragonal, space group D4h
Crystal Cell a=b=7.12 Å, c=6.29 Å
Density 4.22 g/cm3
Mohs Hardness 5, glass-like
Hygroscopic Susceptibility Non-hygroscopic
Thermal Expansion Coefficient aa = 4.43 x 10-6/K; ac = 11.37 x 10-6/K
Thermal Conductivity Coefficient ∥C: 5.23 W/m/K; ⊥ C: 5.10 W/m/K
Crystal Class Positive uniaxial with no=na=nb, ne=nc
Refractive Indices, Birefringence (Dn = ne - no) and Walk-off Angle at 45º (r) no = 1. 9929, ne = 2.2154, △n = 0.2225, ρ = 6.04°  at 0.63 μm
no = 1.9500, ne = 2.1554, △n = 0.2054, ρ= 5.72°   at 1.30 μm
no = 1.9447, ne = 2.1486, △n = 0.2039, ρ= 5.69°   at 1.55 μm
Sellmeier Equation  no2= 3.77834 + 0.069736/(λ2 - 0.04724) - 0.0108133λ2
(λ in μm) ne2=4.59905 + 0.110534/(λ2 - 0.04813) - 0.0122676λ2

Application

YVO4 crystal are widely used in fiber-optic islolators,beam displacers for fiber optical circulators, etc.

 Aperture   1.0 x 1.0 mm2 to 4 x 4 mm 
 Dimension tolerance   +/-0.05mm 
 Wedge Angle tolerance   +/-0.1° 
 Optical axis orientation   +/-0.5°  
 Flatness  Lambda/4 @ 632.8 nm 
 Surface Quality   S/D 20-10 
AR-coating   R<0.2% @1550 or 1310nm 
 Standard Size  1.25mmx1.25mmx0.5mm with 13° or 15° wedge,phi=22.5°  

Circulator

YVO4 Beam Displacer for Circulator

Capability

Common Specification
Dimension Tolerance ±0.05mm
Flatness ≤lambda/ 4 @ 633nm
Wavefront distortion ≤lambda/ 4 @ 633nm
Surface Quality Scratch and Dig 20-10
Beam Deviation < 3 arc minutes
Clear Aperture > 80%
Coating According to customer’s request