Monochromator having an oscilliating mirror beam-diffracting element for spectrometers

A monochromator for single-beam spectrometers, comprising an enclosed housing having an entrance slit, a first optical system for collimating light entering through said entrance slit, a diffracting grate for spectral decomposition of the light entering through said entrance slit and collimated by the first optical system, a driven beam-deflecting element for scanning a monochromatic portion of the spectrally decomposed light and a second optical system for focusing the scanned monochromatic portion of light on an exit slit;

• wherein said driven beam-deflecting element is a mechanically oscillating element with an adjustable amplitude of oscillation and having a scanning mirror (3) attached thereto;
• an electromagnetic coil (9) spaced from said oscillating element (8) for deflecting said oscillating element (8) into resonant oscillations with electromagnetic energy;
• and
• a control circuit (10a, 10b), for periodically connecting and disconnecting current with said coil (9) to stabilize said resonant oscillation of said oscillating element (8) and for adjusting the coil current to adjust the amplitude of resonant oscillation, with a sensor (11a, 11b) for detecting the deflection of said oscillating element (8) and providing an output signal that is used as a feedback signal by said control circuit (10a, 10b);
• whereby when said scanning mirror is arranged with respect to a said diffracting grate having 1200 slits per millimeter, a single sweep of the scanning mirror scans a spectral range of at least about 400 nm.