Complex-Fourier-transform integrated-optic spatial heterodyne spectrometer using phase shift technique

Proposed is a phase shift method that employs a planar waveguide spatial heterodyne spectrometer (SHS) to reveal the input light spectrum. A complex Fourier transformation derives the spectrum directly without any mathematical assumptions, thus eliminating the need for the Lagrange interpolation or deconvolution techniques. The available spectral range is one free spectral range of the SHS and is twice as wide as that available with the conventional method based on a Fourier cosine transformation.