| 摘要 |
The wavelength of a light source (e.g., laser) is stabilized by introducing a collimated beam from the source into a "wedged" etalon, i.e., an etalon having a Fabry-Perot cavity that continuously decreases in width along at least one axis that is normal to the axis of beam propagation. A pair of photodetectors at the output side of the etalon detect respective portions of the beam traversing different cavity widths. The respective output signals of the photodetectors are employed in a feedback loop, whereby the wavelength of the light source is controlled so as to minimize the amplitude difference between the two photodetector signals. The wavelength of the light source can be tuned by varying the ratio of the amplitudes of the photodetector output signals. The wedged etalon can also be used as a multi-channel optical receiver, wherein a multi-wavelength collimated incident beam is introduced into the etalon. An array of photodetectors is disposed at the output side of the etalon, each located at a position corresponding to a different cavity width, so that each photodetector receives one of the component wavelengths of the incident beam. |
