Fabrication and flatness error analysis of a low-stepped mirror in a static Fourier transform infrared spectrometer

摘要

In this study, we propose a Fourier transform infrared spectrometer based on stepped mirrors, which realize static. As the core component of the spectrometer, the low-stepped mirror's structural parameters significantly affect the instrument performance. In order to successfully fabricate a low-stepped mirror with a large area and submicrometer height, we propose a method involving multiple depositions accompanied by a 50% reduction in thickness at every iteration, which can precisely control the accuracy, consistency, and uniformity of the step height. After that, we fabricate a low-stepped mirror consisting of 32 stages and with a step height of 625 run. Through theoretical calculation and simulation analysis, the influence of the step's flatness error on the recovery spectrum is obtained. By increasing the substrate thickness of the stepped mirror, we can reduce the stress of the thin film. We perform experiments using the low-stepped mirror. The low-stepped mirror was incorporated into the Fourier transform infrared spectrometer, and we performed experiments to obtain the spectrum of acetonitrile liquid. The spectrogram of the acetonitrile is obtained by processing the interferogram. (C) 2018 Optical Society of America