Method and device for wavelength locking

摘要

A system for wavelength locking i.e. for maintaining a frequency of an optical signal to within predetermined limits has means for splitting part of the controlled optical signal into at least three sub-beams of which one is a reference beam and two others are provided to an optical element having a periodic output response and to a filter having a monotonic output response. The three detected outputs are analyzed and processed to determine accurately the wavelength of the optical signal and to produce a correcting signal if it is not within the predetermined limits.