Abstract
A vacuum far infrared interferometer designed for the measurement of transmittance, reflectance and refractive index of the samples has been constructed. The instrument is used in the symmetric mode of operation for the measurement of the spectral power and in the asymmetric mode of operation for the spectral phase measurement. To improve S/N ratio without distorsion of the signal, the interferogram is recorded stepwise using a stepping motor and its control system.
The reproducibilities of the transmittance and refractive index of the sample are presented to illustrate the performance of the instrument. The reproducibility of the refractive index is less than±0.3%.
