Variable path length photon trapping spectrometer

摘要

A system and method of photon trapping spectroscopy to vary the path length of light for use in spectroscopy. The systems and method include a rotating reflector with slits for selectively permitting light to enter and exit into a reflection cavity containing a sample to be analyzed. After entering the cavity, but before exiting, the light is trapped and repeatedly reflects back and forth through a sample, effectively increasing the path length of light through a sample. The effective path length is quickly adjustable by altering the rotation speed of the rotating reflector to alter the time in which the light is trapped within the cavity. The systems and methods provide a spectroscope with a wide dynamic range, low detection limits, and usable with broadband and monochromatic light sources throughout the optical region (ultraviolet to infrared).

主权项

1. A variable path length photon trapping spectrometer comprising:
a rotating reflector having a source side, a cavity side, and a slit providing a passage between the source side and the cavity side; a light source that is aligned with the slit when the rotating reflector is at a first rotational position and that emits light towards the rotating reflector and through the slit as the rotating reflector rotates; a cavity that receives the light that passed through the slit; a reflector arrangement positioned opposite the cavity side of the rotating reflector to reflect the light received by the cavity back towards the cavity side of the rotating reflector; and a light detector positioned opposite the source side of the rotating reflector and aligned with the slit when the rotating reflector is at a second rotational position different than the first position to receive the light reflected by the reflector arrangement, which has exited the cavity through the slit, wherein the light received by the cavity reflects between the reflector arrangement and the cavity side of the rotating reflector a plurality of times as the rotating reflector rotates before passing through the slit to the light detector.