  Fourier transform spectroscopy (FTS) has been widely used as an analytical
tool for many applications in science and engineering. In this paper, we
describe the operation principle and practical implementation of an FTS
prototype. First, the structure of an FTS setup based on optical
interferometers is introduced, and its optical and electronic components are
identified. A simple theory is presented to show the Fourier transform
relationship between the measured interferogarm signal at the detector and the
spectral intensity of the source. Then, simulation results based on ray-tracing
method are demonstrated to show the effect of coherent length of the source on
the spectral intensity. Finally, various practical considerations to implement
an FTS setup including noise/interference reduction are discussed, and the
effect of alignment on the measurement accuracy is investigated. Since the
design and implementation of an FTS measurement setup requires the knowledge
from various parts of physics and engineering education, therefore, we believe
that FTS can provide a very comprehensive educational tool for the last year
undergraduate and graduate students.
