Multiple grating optical wavelength monitor

摘要

An optical monitoring arrangement utilizes the properties of a blazed Bragg grating to redirect a portion of an optical signal out of the axial path and into a detecting device. A plurality of blazed Bragg gratings are utilized, each having unique properties, to increase the robustness of the monitor. In particular, by utilizing a plurality of N gratings, the bandwidth of the monitor may be increased N-fold (assuming no overlap in wavelength between gratings). Alternatively, an improvement in resolution can be obtained by utilizing a narrower bandwidth and measuring N times the number of raw data points within that bandwidth. A combination of increase in bandwidth and resolution may be obtained by a comprise between these two extremes. Chirped blazed gratings may also be employed.