Methods and apparatus for fast sweeping a spectral bandwidth in order to distinguish among signals received from effectively wavelength division multiplexed (WDMed) and time division multiplexed (TDMed) optical components on a single fiber. For some embodiments, a method for interrogating optical elements having characteristic wavelengths spanning a sweep range is provided. The method generally includes introducing a pulse of light, by an optical source, into an optical waveguide to interrogate at least a first set of optical elements having different characteristic wavelengths by performing a sweep of wavelengths over a period of the pulse, wherein the period is less than a round-trip time for light reflected from an optical element closest to the optical source to reach a receiver and processing the reflected light to determine a parameter based on the times at which signals are received.

An optical device comprising, an optical input and output device comprising a first input port, a second input port, a first output port and a second output port, and an optical filtering device comprising an input port coupled to the first output port and an output port coupled to the second input port, and an optical amplifying device comprising an input port coupled to the second output port. The optical input and output device is adapted to couple the output port comprised in the optical filtering device to the input port comprised in the optical amplifying device. The optical filtering device comprises a multiple of cascaded phase shifted Bragg gratings, each being adapted to filter an associated respective optical carrier within to produce a respective output signal to the optical amplifying device.

Methods and apparatus for fast sweeping a spectral bandwidth in order to distinguish among signals received from effectively wavelength division multiplexed (WDMed) and time division multiplexed (TDMed) optical components on a single fiber. For some embodiments, a method for interrogating optical elements having characteristic wavelengths spanning a sweep range is provided. The method generally includes introducing a pulse of light, by an optical source, into an optical waveguide to interrogate at least a first set of optical elements having different characteristic wavelengths by performing a sweep of wavelengths over a period of the pulse, wherein the period is less than a round-trip time for light reflected from an optical element closest to the optical source to reach a receiver and processing the reflected light to determine a parameter based on the times at which signals are received.

An optical device comprising, an optical input and output device comprising a first input port, a second input port, a first output port and a second output port, and an optical filtering device comprising an input port coupled to the first output port and an output port coupled to the second input port, and an optical amplifying device comprising an input port coupled to the second output port. The optical input and output device is adapted to couple the output port comprised in the optical filtering device to the input port comprised in the optical amplifying device. The optical filtering device comprises a multiple of cascaded phase shifted Bragg gratings, each being adapted to filter an associated respective optical carrier within to produce a respective output signal to the optical amplifying device.