| Yttrium Vanadate(YVO4) Crystal---Special
crystal For Fiber Optics |
 |
The Yttrium Orthovanadate (YVO4) is a positive
uniaxial crystal grown with Czochralski method. It
has good temperature stability and physical and mechanical
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, interleavers, beam displacers and
other polarizing optics (refer to Table 1) |
Table 1.Comparison of basic properties between
YVO4 and Other Birefringent
Crystals.
| |
YVO4 |
TiO2 |
CaCO3 |
LiNbO3 |
| Thermal
Expansion (/℃) |
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 |
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(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 |
0.4-5μm |
0.4-5μm |
0.35-2.3μm |
0.4-5μm |
A reliable supplier
of YVO4 crystal
CASTECH is one of the earliest companies who devotes
to research and have mastered the advanced growth technique
of YVO4 crystal. Now CASTECH has completed its
strong mass-production line that can provied:
- Various size bulk and finished high quality
YVO4 crystals up to φ35x50mm3 and
φ20x20mm3, respectively;
- Large
quantity YVO4 wedges and displacers used for
fiber optical isolators and circulators, interleavers,
in size 1.25x1.25x0.5mm to 3x3x15mm to meet OEM customer's
requirement.
- Quick
delivery
- Very competitive price
- Strict quality control;
- Very competitive
price
Basic Properties of YVO4
crystals:
| Transparency Range: |
High transmittance
from 0.4 to 5 μm |
| Crystal Symmetry: |
Zircon
Tetragonal, space group D4h |
| crystal Cell: |
a=b=7.12A;c=6.29A |
| Density: |
4.22 g/cm3 |
| Mohs Hardness: |
5, glass-like |
| Hygroscopic Susceptibility: |
Non-hygroscopic |
| Thermal Expansion Coefficiet: |
αa=4.43x10-6/K;αc=11.37x10-6/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 |
| Thermal Optical Coefficient: |
Dna/dT=8.5x10-6/K;dnc/dT=3.0x10-6/K |
| Refractive Indices, Birefringence
(△n=ne-no) and Walk-off Angle
at 45°(ρ): |
no=1.9929,ne=2.2154,△n=0.2225,ρ=6.04°
at 0.63mm
no=1.9500,ne=2.1554,△n=0.2054,ρ=5.72°
at 1.30mm
no=1.9447,ne=2.1486,△n=0.2039,ρ=5.69°
at 1.55mm |
| Sellmeier Equation (λ
in μm): |
no2=3.77834+0.069736/(λ2-0.04724)-0.0108133λ2 ne2=4.59905+0.110534/(λ2-0.04813)-0.0122676λ2
|
YVO4 crystal
application
YVO4 crystal are widely used in fiber-optic isolators,beam
displacers for fiber optical circulators, and interleavers,
etc.
1.Specifications of birefringent
wedges for fiber-optic isolators
| Aperture |
1.0x 1.0mm2
to 4x4mm2 |
| Dimension tolerance |
+/-0.05mm |
| Wedge Angle tolerance |
+/-0.1° |
| Optical axis orientation |
+/-0.5° |
| Flatness |
λ/4 @ 632.8 nm |
| Surface Quality |
20-10 |
| AR-coating |
R<0.2% @1550
or 1310nm |
Standard Size
|
1.25mmx1.25mmx0.5mm with 13° or 15°
wedge, phi=22.5° |
|
|
2.Specifications of
YVO4 beam displacers for fiber-optic circulators
or interleaver
| Dimension tolerance |
W(+/-0.05mm)xH(+/-0.05mm)xL(+/-0.1mm)or(+/-0.003mm) |
| Optical axis orientation |
+/-0.5° |
| Parallelism |
<15 arc sec |
| Perpendicularity |
<10 arc min |
| Flatness |
λ/4 @ 632.8nm |
| Surface Quality |
20/10 |
| AR-coating |
R<0.2% @1550 or 1310nm +/-40nm |
Standard Size
Note:Other sizes and specifications are available upon
request |
2.6x2.6x10mm, θ=45°,Φ=0° |
YVO4 Beam
Displacer for circulator
|
