摘要 |
A compact wavelength monitoring and control assembly (110) for a narrow band (i.e., laser) source is provided, comprising two narrow bandpass, wavelength selective transmission filter elements (130, 160) of Fabry-Perot structure through which two separate collimated beams from a laser source are directed onto two photodetectors (145, 175). A control circuit processes the simultaneously acquired signals from the two detectors (145, 175) as the laser wavelength is varied. The device functions as an optical wavelength discriminator in which the detectors (145, 175) convert optical energy to current (or voltage) for a feedback loop for controlling the laser source. Any one of a large number of discrete, predetermined wavelengths may be chosen for locking using the same device.
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