The FTIR spectrometer design is based on the Michelson Interferometer, featuring:
1. 850nm Laser Source: Provides a coherent light source for generating interference patterns.
2. ZnSe Beam Splitter: Divides the incoming laser beam into two paths, directing them towards the retro reflector mirrors. ZnSe, while limiting the spectrometer range, is not humidity-sensitive like KBr.
3. Retro Reflector Mirrors: Reflect the split beams back towards the beam splitter, ensuring the paths of the two beams recombine.
4. Visible Detector: Monitors the interference patterns created by the laser. This data is used to correct the optical path difference.
5. Pyroelectric Detector: While MCT detectors are highly precise, their cost can be prohibitive. Hence, the plan is to use a pyroelectric detector.
6. Fourier Transform Processing: Translates the time-domain interferogram into a frequency-domain spectrum.