Far-Infrared Narrow-Band Photodetector Based on Magnetically Tunable Cyclotron Resonance-Assisted Transitions in Pure n-Type InSb

We present the possibility of using magnetic field to enhance responsivity and to tune spectral range of far-infrared InSb detector (based on photoconductivity effect) beyond its standard range limited to about 30 cm$\text{}^{-1}$. We show that due to cyclotron resonance assisted transitions we can use it as a tunable detector working up to energies about 180 cm$\text{}^{-1}$ (22 meV). We have used such a detector as a spectrometer for measurements of the Landau emission from GaAs emitter.