Thermal radiation detecting in far-infrared and millimeter ranges

It had been discussed earlier existing of the controlled photoconductivity (PC) in gapless semiconductor Hg 1-x Cd x Te which is induced within the millimeter (MM) and IR ranges by uniaxial stress or high magnetic field. These forces open the energy gap following to E g (P)-bx(s 11 -s 12 ) xP or E g (H)-heH/4m n c respectively and influence the generation and recombination processes in the material. Here, b is a deformation potential constant, s ij is an elastic strain tensor components and m is an electron effective mass in conduction band. In this report a possibility is analyzed of effective detecting of the MM and submillimeter (SMM) thermal radiation by means of the above mentioned controlled PC in combination with a parametric heterodyning of frequencies. The problem seems to be resolvable because the number of spectral lines can be generated with tunable lasers of high enough power within the MM and SMM radiation range. The features are also taken into account that arise in connection with the spectral 'quality' of black-body radiation and in the cases when radiator has a size of order of the wavelength to be detected. It is shown that the ratio can drastically influence the efficiency of detecting process because the time which is necessary to detect this radiator, or object consist of small-size particles.