In a conventional FTIR, the spectral content of the light is analyzed by a Michelson interferometer or other interferometer with a moving arm. The transmitted light intensity is measured by a wavelength-insensitive detector. The interferogram derived from a Michelson interferometer lies in the temporal domain. An alternative method for obtaining the interferogram involving no moving parts is demonstrated. For this, the interferogram lies in the spatial domain. This concept has many applications to sensor systems, for instance, forming a low-cost demodulator for Bragg-grating systems or field-portable spectrometers.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.