Extension of the range of microwave spectroscopy to 1.5 THz
Tret'yakov M. Yu., Krupnov A. F. , Volokhov S. A.
The frequency range of microwave spectroscopy has been extended to 1.5 THz through multiplication of the frequency of a 300-GHz submillimeter backward-wave tube to the fifth harmonic with the help of a new frequency multiplier with a planar Schottky diode. A spectroscopic cell with an acoustic detector was used to select and detect harmonics through observation of spectral lines of gases. Lines of S02 over the range 541-1524 GHz were observed at the second, third, fourth, and fifth harmonics of the fundamental frequency of the backward-wave tube. Ways to expand the range of microwave spectroscopy substantially further are pointed out. © 1995 American Institute of Physics.