Two-beam grating polychromator - has refractive prism for shifting spectrum from diffracting grating, and single octave edge filter in front of two-octave detector array

摘要

Light (12) is diffracted by a grating (14) and fed to a detector array (34) as a spectrum. The detector detects the light over one octave with the light extending in the direction of separation from a short wave end to a long wave end. A refracting prism (20) causes an offset of the spectrum in the separation direction. Short wave light is offset more strongly than long wave light. An edge filter (36) is located in front of the detector array in the longer wavelength region and at a distance from the detector element exposed to the lower end of the detected spectrum. The filter only passes light above a certain wavelength corresp. to double the wavelength of the lower end of the spectrum detected by the array. USE/ADVANTAGE - For detection of spectrum of specimen. over one octave. Effects of higher orders, esp. second order, of grid are eliminated.