Quasi-optical cw mm-wave electron spin resonance spectrometer

Abstract

We describe a novel cw millimeter-wave electron spin resonance (ESR) spectrometer designed to operate in the frequency range of 80–200 GHz and in the temperature range of 2.5–300 K, which may be easily scaled to higher frequencies. The spectrometer uses a bimodal reflection cavity coupled to a circular corrugated guide and uses Gaussian quasi-optics for most of the front-end signal processing. This technique has very low insertion loss and allows a number of sophisticated measurement techniques to be employed including induction operation, which significantly reduces the effect of microphonics and stray reflections. A number of examples are given illustrating the sensitivity of the instrument and the advantages of using ESR at high fields.