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 is an excellent synthetic substitute for Calcite (CaCO3) and Rutile (TiO2) crystals in many applications including fiber optic isolators and circulators, beam displacers, Glan polarizers and other polarizing optics, etc.
Properties:
| Transmitting range | 400~5000nm |
| Crystal Symmetry | Zircon tetragonal, space group D4h |
| Crystal Cell | a=b=7.12 °, c=6.29 ° |
| Density | 4.22 g/cm2 |
| Hygroscopic Susceptibility | Non-hygroscopic |
| Mohs Hardness | 5 glass like |
| Thermal Optical Coefficient | Dna /dT=8.5×10-6 /K; dnc /dT=3.0×10-6 /K |
| Thermal Conductivity Coefficient | ||C: 5.23 w/m/k; ⊥C:5.10w/m/k |
| Crystal Class | Positive uniaxial with no=na=nb, ne=nc |
| Refractive Indices, | no=1.9929, ne=2.2154, Dn=0.2225, ρ=6.04°, at 630nm |
| Birefringence( Dn=ne-no) | no=1.9500, ne=2.1554, Dn=0.2054, ρ=5.72°, at 1300nm |
| and Walk-Off Angle at 45 deg(ρ) | no=1.9447, ne=2.1486, Dn=0.2039, ρ=5.69°, at 1550nm |
| Sellmeier Equation ( l in mm) | no2 =3.77834+0.069736/(l2 -0.04724)-0.0108133l2 ne2 =4.5905+0.110534/(l2 -0.04813)-0.0122676l2 |
YVO4 Specifications:
| Diameter: | Max 25m |
| Length: | Max 35mm |
| Surface Quality: | better than 20/10 scratch/dig |
| Beam Deviation: | < 3 arc min |
| Optical Axis Orientation: | +/-0.2deg |
| Flatness: | < l/4 @632.8nm |
| Wavefront Distortion: | < l/2 @632.8nm |
| Coating: | Coating upon Request |
Applications of YVO4：
YVO4 crystal produced by Photonchina is mainly used to manufacture Birefringent Wedge of optical isolator and Beam Displacer (BD) of optical circulator and optical beam splitter.
YVO4 Wedges or Prisms are also called YVO4 Plates or Blocks.
- YVO4 Wedge, key components of optical isolator.
| Aperture | 1.0x 1.0mm2 to 4x4mm2 |
| Size Tolerance | +/-0.05mm |
| Wedge Tolerance | +/-15% |
| Axis | +/-0.5° |
| Flatness | λ/4 @ 632.8 nm |
| Surface quality | 20-10 |
| Coating | R<0.2% @1550 or 1310nm |
| Standard Size | 1.25mmx1.25mmx0.5mm with 13° or 15° wedge, phi=22.5° |
Notes: other specifications are available upon request
2.YVO4 BD, Beam Displacer, used in fiber circulator
| Size | W(+/-0.05mm)*H(+/-0.05mm)*L(+/-0.1mm)or(+/-0.003mm).
Max Length:35mm |
| Axis | +/-0.5° |
| Parallelism | <15 arc sec |
| Perpendicularity | <10 arc min |
| Flatness | λ/4 @ 632.8nm |
| Surface quality | 20/10 |
| Coating | R<0.2% @1550 or 1310nm +/-40nm |
| Standard Size | 2.6×2.6x10mm, θ=45°,φ=0° |
Notes: other specifications are available upon request.
Comparison of basic characteristics between YVO4 and other birefringent crystals
| Item | YVO4 | TiO2 | CaCo3 | LiNbO3 | |||||
| Coefficient of thermal expansion (/CO) C-Axis | 11.4×10-6 | 9.2×10-6 | 26.3×10-6 | 16.7×10-6 | |||||
| A-Axis | 4.4×10-6 | 7.1×10-6 | 5.4×10-6 | 7×10-6 | |||||
| Reflection coefficient no | 1.9447@1550nm | 2.454@1530nm | 1.6346@1497nm | 2.2151@1440nm | |||||
| ne | 2.1486@1550nm | 2.710@1530nm | 1.4774@1497nm | 2.1413@1440nm | |||||
| Birefringence index (ne-no) | 0.2039@1550nm | 0.256@1530nm | -0.1572@1497nm | -0.0738@1440nm | |||||
| Moh’s hardness | 5 | 6.5 | 3 | 5 | |||||
| Hygroscopy | None | None | Weak | None | |||||
| Photopermeability | 0.4-5μm | 0.4-5μm | 0.35-2.3μm | 0.4-5μm | |||||
