Measurement of wavelength of spectrally narrow-band light source - using reference source, Fabry-Perot interferometer and measurement of intensity maxima separation

摘要

The measurement of the wavelength of a spectrally narrow-band light source involves using a reference light source. Light from both sources (1,6) is fed to a Fabry-Perot interferometer (10), the distance between whose plates (10a,10b) is periodically varied. The intesnity of the transmitted light is measured and the wavelength under investigation determined from the sepration of the intensity maxima (11,12). USE/ADVANTAGE - Esp. for use in microlithography. Enables highly accurate and reliable measurement with samll, low-cost arrangement.