Spectrometer arrangement for helium-neon laser, has diffraction grating and radiation detector arranged in Rowland circle

摘要

A diffraction grating (5) having an alterable lattice constant, is arranged such that the beam (83) from a helium-neon laser (81), is incident on the grating, at a preset angle. A radiation detector (7) receives the beam diffracted from the grating. The diffraction grating and the radiation detector are arranged in a Rowland circle (51). An Independent claim is also included for method of determining wavelength of radiation emitted from a radiation source.