Two material achromatic prism

摘要

A spectrometer comprises a detector array and a prism. The prism comprises a first prism element comprising a substantially crystalline crown material, and a second prism element contacting the first prism element, the second prism element comprising a substantially crystalline flint material. The spectrometer further includes optics configured to direct light at least twice through the prism. The prism is configured to disperse light received from the optics at an incident angle therethrough into constituent spectra in visible and infrared wavelength bands that are dispersed from the prism at angles offset from the incident angle. The constituent spectra are directed onto the detector array with approximately equal dispersion across the visible and infrared wavelength bands. Among other things, desirable material selections for the first and second prism elements are also disclosed.