Abstract
A review is given of spectroscopic research pursued in the Division of Optics at the P N Lebedev Physical Institute (FIAN), which has yielded significant results in recent years. A case in point is primarily the development of instrumentation installed on board artificial Earth satellites and intended for the ultraviolet and X-ray spectroscopy of the solar corona. Furthermore, progress is reviewed in the area of precision atomic spectroscopy, where an arsenal of state-of-the-art techniques enables observing optical resonances ranging in width from several hertz to several hundred hertz.