Waveguide spectrometer to carry out the integrated interferogram scanning

Abstract

A waveguide spectrometer includes at least one substrate layer with at least one surface waveguide extending from an inlet face to guide the received light; at least one evanescent field sampler in the waveguide to out-couple light along the waveguide; at least one light sensing unit to detect the out-coupled light, each electrically connected to an electronic read out system; and means to achieve counter propagating optical signals inside the waveguide to obtain interference between the counter propagating optical signals generating an interference pattern along the waveguide. A compact and simple construction with improved spectral range/bandwidth of the spectrometer can be achieved with at least one modulator integrated into the sampling waveguide structure to enable conditioning of the guided optical signals and for changing the refractive index. The integrated modulator is realized by electrodes placed aside directly neighboured to the guiding core resp. waveguide generating an optical phases shift required for scanning the interferogram.