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Title: A Sagnac Fourier spectrometer

A spectrometer based on a Sagnac interferometer, where one of the mirrors is replaced by a transmission grating, is introduced. Since the action of a transmission grating is reversible, both directions experience the same diffraction at a given wavelength. At the output, the crossed wavefronts are imaged onto a camera, where their Fizeau fringe pattern is recorded. Each spectral element produces a unique spatial frequency, hence the Fourier transform of the recorded interferogram contains the spectrum. Since the grating is tuned to place zero spatial frequency at a selected wavelength, the adjoining spectrum is heterodyned with respect to this wavelength. This spectrum can then be discriminated at a high spectral resolution from relatively low spatial frequencies. The spectrometer can be designed without moving parts for a relatively narrow spectral range or with a rotatable grating. As a result, the latter version bears the potential to be calibrated without a calibrated light source.
 [1] ;  [2]
  1. Lenzner Research LLC, Tucson, AZ (United States)
  2. Univ. of New Mexico, Albuquerque, NM (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Optics Express
Additional Journal Information:
Journal Volume: 25; Journal Issue: 8; Journal ID: ISSN 1094-4087
Optical Society of America (OSA)
Research Org:
Univ. of New Mexico, Albuquerque, NM (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
47 OTHER INSTRUMENTATION; Fourier transform spectroscopy; heterodyne; spectroscopy
OSTI Identifier: