Patent ID: 7456957

Claim:
A spectrometer for monitoring the magnitude of a broadband light beam as a function of wavelength comprising: a grating for angularly dispersing an incident light beam as a function of wavelength; a linear detector array for receiving and monitoring the dispersed light beam, with the incident beam, the grating and the detector array being positioned in a substantially Littrow condition and with the grating being tipped with respect to the incoming beam to induce conical diffraction to thereby spatially separate the path of the diffracted beam from the incident beam, with said conical diffraction resulting in the footprint of the dispersed light having a non-linearity in a direction perpendicular to the axis of the array; and a first optical element located between the grating and the array for reducing the non-linearity caused by the conical diffraction so the registration of the footprint with the array is improved.