摘要 |
An apparatus for stabilizing the wavelength of light emitted by a laser or light source comprising a divider for dividing a sample of emitted light into a first and second portion; a first photodetector configured to measure an intensity of the first portion and a second photodetector configured to measure an intensity of the second portion, the second photodetector configured to receive the emitted light via an optical frequency discriminator, such as a dielectric coating, wherein the optical frequency discriminator is configured to modify the intensity of the emitted light at the second photodetector as a function of an optical frequency of the emitted light; and a processor configured to maintain a desired level corresponding to a ratio of the intensity measured by the first photodetector and the intensity measured by the second photodetector, so as to provide a feedback control signal to adjust the wavelength of the emitted light. In one embodiment, the first and second photodetectors are photodetector diodes having a base electrode, a first electrode and a second electrode. The diode is configured to generate an electrical current between the base electrode and the first electrode corresponding to the intensity of light received by the first photodetector and to generate an electrical current between the base electrode and the second electrode corresponding to the intensity of light received by the second photodetector. In still another embodiment, the sample is a back-facet emission emitted by the source, wherein the entire apparatus is disposed on a silicon chip having the frequency discriminating dielectric coating applied directly to its surface.
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