| 摘要 |
<p>A system for maintaining the wavelength scale calibration of diffraction grating based spectrometers and monochromators is disclosed. The system utilizes the approximately fixed angular relationship between diffracted and undiffracted light emanating from the diffraction grating to maintain the calibration of an instrument. One or more photodetectors are used to measure shifts in an undiffracted image due to mechanical misalignments that cause errors in the instrument's wavelength scale. Once direction and degree of shift known, the instrument is recalibrated either by adjusting various mechanical and/or optical structures within the instrument to shift the undiffracted images by an amount equal to, but in a direction opposite the measured shift so that the diffracted light is likeweise shifted, or by relabeling the wavelength scale outputs by an amount derived from the measured shift.</p> |
