Fourier transform ultraviolet-visible spectrometer based on a beam-folding technique

A beam-folding technique in optical interferometry, where the number of beam folds used can be very large, is reported. This technique can be used as a low-cost position-tracking method in a Fourier transform spectrometer (FTS) to cover the broad spectral range from UV to IR. The main advantage gained is the simple position-tracking algorithm used in sampling the interferogram. We have developed a UV-visible FTS, whose wavelength coverage is limited only by the optical elements (350 nm-1 μm with off-the-shelf components). Preliminary results show that it can achieve a resolution of ∼4 cm^-1 even with a ball-bearing translation stage.