Abstract

Although the output signal of a Fourier transform spectrometer (FTS) must be transformed to obtain a spectrum, the benefits of the two beam interferometer over the grating spectrometer are such that the FTS is more advantageous for some spectral applications. The increased throughput of the FTS is always an advantage and the multiplex capability is sometimes a benefit. The disadvantage of the Michelson interferometer implementation of the FTS is the need for a precision mirror drive and the lack of being field widened.¹ In a holographic Fourier transform spectrometer (HFTS) the image of the source is sheared by means of stationary mirrors and thus does not suffer from the above problems. The nonlinearity and low dynamic range of the photographic film normally used in HFTS can be eliminated by the film's replacement with a CCD array.² The spectrum is obtained from the interferogram by digital signal processing. We are building and evaluating such a digital array scanned Fourier transform spectrometer and testing its suitability for use on an automatic spectrophotometric telescope.

© 1989 Optical Society of America