The Three-Level Gas Maser as a Microwave Spectrometer

Abstract

A method of microwave spectroscopy using three-level maser action is described, and some preliminary experiment on HDCO is given. A b–type transition, 3₀₃←2₁₂, which is connected with a a-type transition 2₁₁←2₁₂, has been definitely assigned by the observation of three-level master action. Moreover, the weak transition, 3₀₃←2₁₂, was observed with very good signal to noise ratio by using the strong transition, 2₁₁←2₁₂, as a detecting transition. Theories of the three-level maser action in gases are also compared with experiment and shown to be in good agreement. Further applications of the three-level gas maser as a spectrometer as well as an amplifier are discussed.