Rapid Scanning with the Fabry-Perot Etalon

A brief description of the principles of the scanning Fabry-Perot spectrometer is followed by an introductory survey of the various F-P spectrometers that have been used successfully. The limits of rapid scanning F-P spectroscopy are considered with regard to time resolution, wavelength resolution, and the size of the wavelength interval scanned. These considerations indicate that it is already feasible to scan a wavelength interval up to approximately 30 A in times down to 0.3 microsec with an over-all finesse of 20, but under these conditions the useful aperture is restricted to only 1-cm diam. Present spectrometers are limited in their time resolution by the breaking strengths of ceramic components. Finally, various applications of the rapid scanning F-P spectrometer are discussed.