Ex) Article Title, Author, Keywords
New Phys.: Sae Mulli 2021; 71: 539-546
Published online June 30, 2021 https://doi.org/10.3938/NPSM.71.539
Copyright © New Physics: Sae Mulli.
Seung Seok LEE, Eun Seo CHOI*
Department of Physics, Chosun University, Gwangju 61452, Korea
In this paper, we describe the characteristics of interferometry using a chirped fiber Bragg grating as the reference arm of a fiber-optic interferometer and propose a method to improve the maximum measurement displacement. This fiber-optic interferometer generated a symmetrically chirped interference signal due to the group delay given by the dispersion characteristics. The position information of the reflector at the sample arm could be restored through a signal processing technique for extracting the envelope from the interference signal. Interfering signals were measured while increasing the displacement of the reflector at the sample arm at intervals of 500 $\mu$m from 0 to 6.5 mm. From the measured interference signal, the displacement information of the reflector at the sample arm could be restored with a resolution of 100 $\mu$m. The proposed technique was able to overcome the measurement limitations of the existing spectrometer-based dispersive interferometer, and the proposed method can provide improved depth information in various optical measurements and optical imaging applications based on interferometers.
Keywords: Chirped fiber bragg gratings, Fiber-optic interferometer, Group delay