Sampling precision consideration for high resolution Fourier transform spectroscopy

The use of dispersive Fourier transform techniques in interferometry allows the measurement of absorption coefficient and refractive index spectra with great precision. Normally, the sharp rotational lines of gaseous molecules can be resolved once higher resolution spectroscopy is employed. The high resolution requires recording of interferogram data points over an extended mirror movement. The issue of sampling size was never considered in the past. This paper presents the importance of using precise step motors for data sampling in these highly sensitive measurements by using two different step motors.