Spectro-specific diffractive elements as sources of radiation.

摘要

A method of producing a light beam having a wavelength spectrum with characteristics of an absorption spectrum of a molecular species or mixture of molecular species of interest comprises the illumination of a diffractive element (10) with a broad-band optical source (42) to diffract light of wavelengths absorbed by the molecular species. The resulting diffracted beam is selected from an appropriate portion of the far-field radiation pattern. <IMAGE>