A frequency-shifted local oscillator beam was produced by a rotating radial grating in an infrared heterodyne detector operating with a CO2 laser. Reduction in mixing efficiency due to beam distortion on diffraction from the radial grating was predicted and observed. The simplicity of the device makes it attractive in some applications of heterodyne detection, e.g. coherent lidars.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials