Principles and performance of an electron spin echo spectrometer using farinfrared lasers as excitation sources

We have built an electron spin echo spectrometer operating at 604 GHz, exte nding the frequency limit of existing spectrometers by more than a factor o f 4, In order to handle this high frequency we have used optical techniques , i.e,, molecular gas lasers for the excitation pulses and far infrared tec hniques for the heterodyne detection system. The different components of th e spectrometer are described in detail and first experimental results are g iven. (C) 1999 Academic Press.