Spatial heterodyne planar waveguide spectrometer: Theory and design

We review the theory and design of a novel type of stationary spectrometer in planar optical waveguides. These spatial heterodyne spectrometers are based on arrayed Mach-Zehnder interferometers and offer high resolution and increased optical throughput (étendue). A stationary Fourier technique is employed to reconstruct the input spectrum from the Mach-Zehnder outputs. Calibration mitigates waveguide fabrication errors and can be readily implemented in the spectra retrieval algorithm. Sensitivity to errors calibration measurements is numerically simulated.