Patent ID: 7796252

Claim:
An apparatus for high speed spectroscopic sample analysis, comprising: a light source for illuminating a sample; an oscillating diffraction-grating mounted on a rotatable shaft for breaking broadband light from the light source into spectrographic constituent wavelengths; a programmable stepper motor having a shaft connected directly to said diffraction grating for direct drive thereof, and controlled incremental rotation of said diffraction-grating over an angular range in order to scan each of said constituent wavelengths; an encoder mounted proximate said diffraction-grating for outputting pulses corresponding to an angular position of said diffraction-grating within said angular range; and a processor in communication with said programmable stepper motor and said encoder for incremental control of the rotation of said stepper motor and diffraction-grating within said angular range in accordance with said encoder output pulses, said processor time-stamps each outputted encoder pulse within said angular range and computes a rotational velocity of said diffraction grating for each outputted encoder pulse.