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
|Refractive indices @589nm
||2.26(o), 2.41(e)||1.9(o), 2.6(e)|
|Sound velocity in the  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  direction M2 [x10-18 s3/g]||370||800|