Spectrally Resolved Longitudinal Spatial Coherence Interferometry

Abstract: We present a one-dimensional (1-D) imaging technique that uses longitudinal spatial coherence interferometry to encode a scene’s spatial information onto the source’s power spectrum. By spectrally resolving the output using a spectrometer, a channeled spectrum is measured. Fourier transformation of the channeled spectrum yields a measurement of the incident scene’s angular spectrum. The theory is presented to exhibit analogies to conventional Fourier transform spectroscopy of the power spectrum. Experimental validation of the technique is demonstrated, using a Fabry–Perot etalon, for the reconstruction of 1-D sinusoidal and randomly generated angular spectra. Root mean square error between the input and output angular spectra is demonstrated, on average, to be 12.7% and 13.6% for single-frequency and random spectra, respectively.