The performance and the characteristics of an interferometric double-mirror spectrometer with uncollimated light are studied by measuring spectra of different radiation sources. The stationary interferometer is fabricated without a beam splitter or moving components. The measured interferogram visibilities, which are limited by the size of the source aperture, agree with the theoretical predictions for a slit and a circular source aperture. By background subtraction the effect of detection nonuniformity can be radically reduced to increase the dynamics and the resolving power of the spectrometer. We used a mercury pencil lamp for measurement and found that the dynamic range was ~ 80 dBm. When isolated spectral lines are measured, the resolving power can be improved by squeezing more than half of a spatial interference cycle onto one pixel. The maximum resolving power reached in measuring the spectra of a diode laser was 1600. The instrument is applicable to a wide range of measurements, such as the recording of temporally variant, wideband radiation sources and the monitoring of laser wavelength.
© 1992 Optical Society of America
Original Manuscript: September 17, 1991
Published: July 20, 1992
Marja-Leena Junttila, "Stationary Fourier-transform spectrometer," Appl. Opt. 31, 4106-4112 (1992)