Broad range bimodal microcavity in-line Mach-Zehnder interferometers

• Published in: Optics and laser technology Vol. 145; p. 107503
• Main Authors: Eftimov, T., Arapova, A., Janik, M., Bock, W.J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2022; Elsevier BV
• Subjects: Bimodal fibers; Broad range; Cut off wavelength; Femtosecond laser; Free spectral range; In-line fiber interferometers; Mach-Zehnder interferometers; Material dispersion; Refractivity; Sensitivity; Visibility; Bimodal fibers; Mach-Zehnder interferometers; Sensitivity; Material dispersion; Femtosecond laser; Broad range; Visibility; In-line fiber interferometers; Free spectral range
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2021.107503

•In-line MZ interferometers in bimodal optical fibers are fabricated and studied.•A broad spectral range of operation from 500 nm to 1700 nm is observed.•Analysis of the wavelength dependence of sensitivity and free spectral range is performed.•Material dispersion of the fiber and surrounding medium is taken into account.•Relative coupled power and visibility are analyzed theoretically and experimentally. We report on the fabrication and study of a broad range microcavity in-line Mach-Zehnder Interferometers (BR-μIMZI) operating in the range from 500 nm to 1700 nm. The BR-μIMZI is based on a single-mode fiber in the near-infrared (NIR) range. For wavelengths above the cut-off wavelength λc, the interferometric responses are due to the fundamental LP01 mode, while below λc – to the second LP11 mode. We derive expressions for the spectral dependencies of the sensitivity to surrounding refractive index (SRI) changes and of the free spectral range (FSR) taking into account the material dispersion of the fiber and the SRI which are confirmed by experimental measurements. The expression for the relation between relative coupled power and visibility have been derived and experimentally measured.