Features of thermal radiation of plane-parallel semiconductor wafers

The spectra and angular distribution of thermal radiation from semitransparent plane-parallel semiconductor wafers are theoretically and experimentally investigated. It is shown that the spectrum of thermal radiation from these objects is oscillatory due to multiple-beam interference, and the radiation pattern has the lobes. The measurements are performed in the region of free-carrier absorption of n-GaAs and n-Si. It is concluded that the results of this study can be used for calculating new controlled IR-radiation sources.