Acousto-optical Components


Calomel is suitable for the construction of acousto-optical devices. To illustrate, Calomel´s AO figure of merit is comparable with that of a tellurium dioxide TeO2 and more than one order better than that of lead molybdenate PbMoO4. The transparency of Calomel (0.38 to 20µm) enables the use of AO units in a broad spectral range (compared with TeO2) covering a very interesting thermal IR region. No acousto-optical tuneable filter for interesting spectral TIR region is currently available on the market.



Calomel properties make it a great candidate for production of acousto-optical tuneable filters (AOTF). The AOTF may be exploited as broadband “dispersive medium” which benefits of large wavelength operative range, interferometer-like spectral resolution, compact design and no moving parts. Hyperspectral imagers based on the AOTF for TIR region, have a wide range of potential applications such as atmospheric gas detection, water management, fire hazards, volcano monitoring, astronomy, oil spills detection, surveillance, etc.


Calomel, as a medium for delay of acoustic waves offers the longest possible time window (up to l50 µsec) of any known material. Such a slow shear acoustic wave can significantly reduce the size of generally used delay lines. Such a property makes Calomel ideal for signal processing – correlation, convolution and filtering, noise reduction, etc.

Comparission of Paratellurite and Calomel for AO applications
Material TeO2 Hg2Cl2
Refractive indices @589nm
2.26(o), 2.41(e) 1.9(o), 2.6(e)
Birefringence @589nm
0.15 0.7
Sound velocity in the [110] direction [m/s] 620 347
Possible frequency bandwidth at 100 MHz [MHz] 45-47 20-25
Achievable resolution with 5 mm aperture [points] 37 330
Figure of merit in the [110] direction M2 [x10-18 s3/g] 370 800
Calomel AOTF breadboard

Interested in Calomel AO components? Please contact us on info(at) for inquiry.