In a spectroscopic instrument having a spherical grating to disperse incident light into a spectrum, the grating is oscillated on axis to scan the light passing through an exit slit through the spectrum or a portion of the spectrum. The axis of rotation of the grating is shifted to be displaced from...http://www.google.es/patents/US6031608?utm_source=gb-gplus-sharePatente US6031608 - Spectroscopic instrument with offset grating to improve focus
Spectroscopic instrument with offset grating to improve focus
