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Abstract

The present invention discloses a method for demodulating, processing and multiplexing the signals from an array of structurally integrated Bragg grating laser sensors in an optoelectronic element in order that this sensing information can be transmitted from the structure by means of a single channel and a user friendly interconnect or free-space propagation. The invention also discloses a method for determining the wavelength of narrowband optical signals such as arises from Bragg grating laser sensors and includes, for each sensor, processing the optical signal through a spectral filter with a spectral transmission function that can be accurately translated by a control parameter which has been calibrated with respective to wavelength. The filtered signal is compared to the reference signal at different values of the control parameter to determine a value of the control parameter where a predetermined relationship of the spectrally filtered signal and the reference signal is achieved. This allows the wavelength to be determined. Apparatus for carrying out the method is also disclosed. A preferred embodiment involving the use of a multiple quantum well electroabsorption device to perform both spectral filtering and detection is also disclosed. The method and apparatus have particular application with lasers and laser sensing arrangements for smart structures.

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First Claim