An IR-Radiometer with Internal Signal Modulation

An infrared (IR) radiometer electrical circuit on the basis of photoresistors and photodiodes made of silicon doped with zinc (Si<Zn>) as well as the narrow bandgap semiconductor alloy Pb_0.78Sn_0.22Te is presented. In the circuit suggested a bridge with the photoreceiver connected to the radiometer input and immediately fed by signal generators functions as a radiation modulator. The threshold sensitivity turned out on a recorder is 2·10^?13 W·Hz^?1/2 (for the n⁺?n?n⁺ structures made of Si<Zn>, λ=0.8?l.2μm, T=300K); 1.4·10^?15W·Hz^?1/2 (for p⁺?n?n⁺ S-diodes on the basis of Si<Zn>, λ=0.8?1.2μm, T=300K) and 10^?12W·Hz^1/2 (for photodiodes on the basis of Pb_0.78Sn_0.22Te, λ=8?13μm, T=77K).