Fe:LiNbO3 Crystals
Fe:LiNbO3 crystal is one of the most popular photorefractive materials
due to it’s high photorefractive sensitivity, excellent EO and chemo-mechanical
properties, availability in large sizes at moderate cost. This opens the way
for wide application of Fe:LiNbO3 both in R&D and practical devices for
holographic storage, optical memories and information processing.
ELAN offers Fe:LiNbO3 elements fabricated to customer’s specifications
of fully poled, high optical quality crystals grown by Czochralsky method. Wide
range
of available dopant levels enables to adjust material properties to specific
customer application.
Material propeties
| Chemical Formula |
LiNbO3 |
| Doping Ions |
Fe2+, Fe3+ |
Doping levels
( mol.% Fe2O3 in the melt )
|
0.005; 0.02; 0.05; 0.1 (other on request) |
| Crystal symmetry |
Trigonal, 3m |
| Density, g/cm3 |
4.64 |
| Mohs hardness |
5 |
| Melting point , °C |
1255 (Tc=1140 ) |
| Transparency range, nm |
0.35 – 5.5 |
| Refractive Index at lambda=0.63
nm |
2.29 (no)
2.20 (ne) |
| ElectroopticalCoefficient ,pm/V (at lambda=0.63
nm) |
32 (r33) 6.8 (r22)
10 (r31) |
Dielectric Constant
( low frequency)
|
85 (e11)
30 (e33)
|
NOTE
- Crystals are grown from congruent melt.
- Finished elements are available
in sizes (3–20)x(3–20)x(3–20) mm3.Wafers with dia. up to 40 mm, or 30x30
mm square, 0.5 - 5.0 mm thick are available.
- Polish standard: 20/10
S/D, lambda/4 flatness, parallelism < 2’
- Coatings available:
a) AR @ 514 nm, 532 nm or other on request
b) ITO conductive/transparent coatings
- Optical absorption in Fe:LiNbO3 strongly depends on doping level and
wavelength. For standard concentration of 0.05% it is near 1 cm-1 at
532 nm but it can be additionally adjusted in some limits by annealing
process in proper atmosphere due to change relative concentrations of
Fe2+ and Fe3+ ions in the LiNbO3 matrix.
- Standard orientations: Z-cut, 45 deg. cut and 90 deg. cut.
Other orientations are available on request.
- Other photorefractive crystals available from ELAN: BGO, BSO, BTO,
Fe:Ti:LiNbO3, Fe:Ti:Ce:LiNbO3, crystals for UV
photorefraction (LiTaO3,
LiIO3, undoped LiNbO3).
|
