Acousto-Optic Crystals
The effect of light diffraction by acoustic wave is wide used in the
Acousto-Optic (A-O) Devices. Typically, ultrasonic wave is generated
with LiNbO3 piezotranducer bonded to A-O crystal. The intensity, direction
and wavelength of the diffracted light are related with power and frequency
of RF signal applied to piezotransducer. The following A-O devices
can be produced: modulators, deflectors, A-O tunable filters (AOTFs),
laser
Q-switches, RF spectrum analyzers.
ELAN offers a number of AO crystals fabricated according to customer's
specifications. Tellurium Dioxide (TeO2) and Lead Molibdate
(PbMoO4) are commonly used due to successful combination of
wide transparency range, high A-O figure of merit, suitable acoustic
properties (see below). Grown by Czochralsky method TeO2 and
PbMoO4 have the following features:
- large boule sizes: dia. (40 - 50) mm, length (40 - 60) mm;
- high optical homogeneity controlled by interferometer and shadowgraphy
(Schlieren) method;
- low absorption and scattering (inspected with He - Ne laser);
AO elements which we supply are manufactured as a rule according to
customers specifications and have the following features:
- wide sizes range from as small as 5 x 5 x 10 mm to as large as 25
x 25 x 50 mm;
- X-ray orientations of crystals according to any customer's specifications
with accuracy up to 1.5 arcmin.;
- high quality polishing: up to10/5 Scratch/Dig per MIL-013830A, with
λ/8 flatness and 10 arc. sec. parallelism (best parameters);
- single wavelength or broadband AR coatings are available according
to MIL-C-14806A with less than 0.5% reflectivity per surface for broadband
and 0.2% for single wavelength coating;
- technical consultance service is available. Our specialists can calculate
and offer you the most reasonable configuration of AO element depending
on your application. Typical elements we produce are applied in modulators
(including multichannel), deflectors (including 2D), AOTFs and Q-switches.
Other AO materials available from ELAN:
- Quartz and Fused Silica - for high power laser Q - switches;
- Ge, GaAs - for IR range;
- LiNbO3 and LiTaO3 - for high frequency AO devices,
for integrated AO devices and for piezotransducers.
For additional property data, please contact ELAN staff.
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