Tandem dispersive range monochromator

摘要

Aspects of a monochromator are described herein. In one embodiment, the monochromator includes a light source that provides light, a diffraction grating including a first diffraction grating and a second diffraction grating, a grating drive motor that rotates the diffraction grating to provide dispersed wavelengths of light, a detector that detects a portion of the dispersed wavelengths of light, and processing circuitry that controls a grating drive motor to regulate an angular velocity of the grating based on an angular orientation of the diffraction grating. By using a diffraction grating having multiple, different dispersive surfaces, measurements of relatively high precision and quality may be taken throughout a wider spectral range. In another aspect, the processing circuitry controls a sample drive motor to vary an angle of incidence of the dispersed wavelengths of light onto a sample for evaluation.

主权项

1. A monochromator, comprising:
a light source; a diffraction grating comprising a first periodic surface region and a second periodic surface region; a grating drive motor that rotates the diffraction grating to provide dispersed wavelengths of light from the light source; a detector configured to detect at least one of a portion of the dispersed wavelengths of light or a reflection thereof; and processing circuitry configured to control the grating drive motor to regulate a first angular velocity of the diffraction grating over a first range of motion for the first periodic surface region of the diffraction grating and to regulate a second angular velocity of the diffraction grating over a second range of motion for the second periodic surface region of the diffraction grating based on an angular orientation of the diffraction grating.