Abstract

The spectrometer is of the type developed by K. Evenson.’ Radiation from two CO₂ lasers and microwave radiation are mixed on a metal-insulator-metal (MIM) diode to generate tunable far-infrared (FIR) radiation (Fig. 1). With a choice of appropriate pairs of laser lines, FIR radiation at frequencies up to 6 THz can be generated. Center frequencies of molecular spectral lines can be determined with a typical accuracy of 10 kHz. This means that the frequency measurements in the FIR region have now an accuracy comparable to that in the microwave region.

© 1995 IEEE