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Tellurium Dioxide (TeO2 or Paratellurite) and Lead Molybdate (PbMoO4 or PM)
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Tellurium Dioxide (TeO2 or Paratellurite)
The effect of light diffraction by acoustic wave is widely used in the Acousto-Optic (AO) Devices. Typically, ultrasonic wave is generated with LiNbO3 piezotranducer bonded to AO crystal. The intensity, direction, and wavelength of the diffracted light are related with power and frequency of RF signal applied to piezotransducer. The following AO devices can be produced: modulators, deflectors, A-O tunable filters (AOTFs), laser Q-switches, and RF spectrum analyzers.
   Laser quality Tellurium Dioxide (TeO2 or Paratellurite) is an excellent piezo-optical material. It is extensively used because of it's high acousto-optical figure of merit in making acousto-optical modulators, imaging devices, splitters, deflectors, tunable polarisation filters, radio frequency spectral analysers and other acousto-optoelectronic equipment for laser radiation control. TeO2 crystals are grown by the Czochralsky method. It has higher damage threshold and better optical quality if compared with TeO2 crystals grown by some other methods.
   Lead Molybdate (PbMoO4 or PM) crystal is one of the most efficient materials used for acousto-optic devices. It has been extensively used for acousto-optic modulators, deflectors and phase-shifters. Crystals of Lead Molybdate with the diameter of up to 60 mm and 60 - 80 mm in length are grown by the Czochralsky-Kyropulos method. Lead Molybdate AO elements possess low optical losses, high optical homogeneity, stability to laser radiation. High crystal homogeneity also allows vacuum thermo - pressure bonding for large aperture devices.
MAIN PROPERTIES:

Material TeO2 PbMoO4
Crystal class Tetragonal Tetragonal
Lattice constant, A a = 4.796, c = 7.626 a = 5.432, c = 12.107
Density, g/cm3 6.00 6.95
Melting point , C 733 1060
Mohs hardness 4 3
Color Colorless Colorless or light yellow
Transparency range, nm 0.35 - 5.0 0.42 - 5.5
Refractive indices @ 633 nm no = 2.26, ne = 2.41 no = 2.38, ne = 2.25
Thermal expansion coefficient, 10-6/ C (@20°C) aa = 19, ac = 6 aa = 10, ac = 25
Thermal conductivity , mW/cm C 30 15
Dielectric Constant (@ 100 KHz) ea = 25, ec = 22 ea = 40, ec = 34
Acoustic velocities , km/sec
Shear wave propagating along <110>
Longitudinal wave propagating along <001>

0.617
4.26


3.63
Acoustic attenuation at 500 MHz , dB/cm
Shear wave propagating along <110>
Longitudinal wave propagating along <001>


2.3


2.5
Figure of merit M2 , (10-18 sec3/g)
Slow shear mode along <110>
Longitudial mode along <001>

1200
34.5


37
Additional info about A-O properties: MORE ... MORE ...

High quality crystals with large dimensions are routinely fabricated and stocked for quick delivery. We supply elements made from TeO2 or PbMoO4 up to the following sizes:
- along<110>axis - 40-50 mm
- diameter - 70 mm

I N Q U I R Y    F O R M :

Material:
Quantity of elements:
Application:

polished sites:

BLOCK    or  BLOCK
 a-b b-c a-c
or d  
Orientation:
(if applicated)
Dimensions/Tolerances:
For example:
10.0 +/- 0.1
AR-coating or electrodes:
a = mm;
c = mm
b = mm or
dia. = mm;
This field is for additional information such as application,
comments, add. requirements etc.

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