Patent ID: 7302179

Claim:
An optical performance monitor, comprising: an optical isolator having an output optically coupled to an input of a means for demultiplexing the input optical signals into a pre-selected number of wavelength bands, each wavelength band containing a pre-selected number of wavelength channels, the optical isolator having an input optically coupled to the input optical signals, the means for demultiplexing the optical signals having a number of outputs equal to the pre-selected number of wavelength bands with each output being optically coupled into an associated optical branching device, each optical branching device having a first circulating port being optically coupled to a first end of an associated length of optical fiber, each optical branching device having an output port optically coupled to an associated detector; each length of optical fiber having a fiber Bragg grating array including a the same number of spatially-separated fiber Bragg gratings, each of the fiber Bragg gratings having a different associated Bragg wavelength, the length of optical fiber having a second end being a low reflection termination; tuning means attached to each of the spatially-separated fiber Bragg gratings for inducing a pre-selected amount of change in both fiber Bragg grating period and refractive index in each fiber Bragg grating for shifting the associated Bragg wavelengths of each of the fiber Bragg gratings among a pre-selected number (L) of positions, wherein when a pre-selected fiber Bragg grating in each length of optical fiber is switched to coincide with a pre-selected wavelength channel, the pre-selected wavelength channels in each fiber are reflected back through the optical branching device attached to each length of optical fiber and out through its output port into the associated detector connected thereto, whereupon the wavelength channels of each wavelength band are interrogated to determine pre-selected properties of the optical signals, wherein each spatially-separated fiber Bragg grating in different optical fibers but in the same corresponding fiber positions is attached to a common tuning means such that all the fiber Bragg gratings in the same corresponding fiber positions are switched at the same time.