Crystals  Birefringent Crystals YVO4
Introduction
The yttrium orthvanadate (YVO4)
is a positive uniaxial crystal grown with Czochralski
method. It has good temperature stability and physical and
mechanical properties, wide transparency and large birefringence,
so it is also ideal for optical components such as fiber
optical isolators and circulators, beam displaces and other
polarizing optics, etc.
Basic Properties:
Transparency
Range
|
high
transmittance from 0.4 to 5mm
|
Crystal
Symmetry
|
Zircon
Tetragonal, space group D4h
|
Crystal
Cell
|
a=b=7.12Å;
c=6.29 Å
|
Density:
|
4.22
g/cm3
|
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
|
Thermal
Optical Coefficient:
|
dna/dT
= 8.5x10-6/K; dnc/dT = 3.0x10-6/K
|
| |
0.6341 mm |
1.30 mm
|
1.55 mm
|
| Refractive Indices: |
no |
1. 9929
|
1.950
|
1.9447
|
ne |
2.2154
|
2.1554 |
2.1486
|
Birefringence
(Dn
= ne - no)
|
0.2225,
|
0.2054
|
0.2039
|
Walk-off
Angle at 45º (r)
|
6.04º at
|
5.72º
|
5.69º
|
Sellmeier Equation (l in mm):
no2=3.77834
+ 0.069736/(l2 - 0.04724) - 0.0108133l2
ne2=4.59905
+ 0.110534/(l2 - 0.04813) - 0.0122676l2
Comparation
with 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 |
2x10-6 |
Refractive Index
|
no |
1.9447
@550nm |
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
@440nm) |
| Mohs Hardness |
5 |
6.5 |
3 |
5 |
| Transparency range |
0.4-5mm |
0.4-5mm |
0.35-2.3mm
|
0.4-5mm |
Applications of YVO4 Crystals:
Following drawings are the simple demonstrations
of how the YVO4 crystals are used in Fiber Optic
Isolator,
Beam Displacers, Circulators and interleaver.
|
Circulator |
 |
Interleaver |
Specifications
| |
Dimension tolerance: ±0.05 mm
Wedge Angle tolerance:0.1°(wedges)
Optical axis orientation: ±0.5°
Parallelism: <15 arc sec
Perpendicularity: <10 arc min
Flatness: l/4
@ 632.8 nm
Surface Quality: 20-10
AR-coating: R<0.2% @1550±30nm |
|
|
|
|
