Ultrasensitive Gas Refractometer Using Capillary-Based Mach-Zehnder Interferometer.

ABSTRACT: In this paper, we report a capillary-based Mach-Zehnder (M-Z) interferometer that could be used for precise detection of variations in refractive indices of gaseous samples. The sensing mechanism is quite straightforward. Cladding and core modes of a capillary are simultaneously excited by coupling coherent laser beams to the capillary cladding and core, respectively. An interferogram would be generated as the light transmitted from the core interferes with the light transmitted from the cladding. Variations in the refractive index of the air filling the core lead to variations in the phase difference between the core and cladding modes, thus shifting the interference fringes. Using a photodiode together with a narrow slit, we could interrogate the fringe shifts. The resolution of the sens

SUBMITTER: Chen H 

PROVIDER: S-EPMC7070851 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature