Abstract

As a sensing mechanism for broadband (contactless) millimeter-wave spectroscopy of planar mesoscopic systems at cryogenic temperatures, bolometric detection or the photoconductive response of the sample is usually employed. Conventional sources of radiation, such as backward-wave oscillator tubes or Gunn diodes, are then modulated for lock-in detection. In most cases, the output power from these sources varies as they are tuned, changing the thermal load on the system being studied. Furthermore, such conventional sources rarely offer over a decade of frequency coverage, limiting the range available for probing these systems.

© 1995 Optical Society of America