Abstract: A distributed optical fiber sensor system including a patterned array of kly reflecting broadband gratings or other sensors serially disposed along a common fiber. The laser sources are multiplexed onto the fiber and are propagated through a directional coupler toward the sensors. The return signals are directed by the directional coupler to a demultiplexer that separates the signals by center frequencies and sends each to a respective detector. All reflection signals generated by a single input pulse of a given wavelength are detected prior to the input coupling of the next input pulse of that wavelength, the input pulse repetition period being T.gtoreq.Nt.sub.0, N being the number of grating sensors and t.sub.0 being their spacing or separation in optical propagation time.