Ultra-Sensitive Microwave-Photonic Optical Fiber Interferometry based on Phase-Shift Amplification


This paper proposes phase-shift-amplified optical fiber interferometry based on microwave photonics (MWP) for sensing applications with substantially-improved sensitivity. The principal idea of the system combines a destructive interference-based phase-shift amplification technique with optical carrier-based microwave interferometry (OCMI). The phase sensitivity of the OCMI system is significantly improved due to the phase amplifier, and more importantly, can be adjusted by simply varying the amplitude ratio of the two beams used in the interferometer. The amplification of the phase sensitivity is numerically investigated and experimentally demonstrated using a Mach-Zehnder interferometer for temperature and strain measurements. The measurement results accurately match theoretical predictions. Moreover, we demonstrate that light-scattering dots in the optical fiber core, created by tightly-focused femtosecond laser pulses, can be used to precisely tune the amplitude ratio of the two-beam interferometer. We postulate that amplification of several orders of magnitude in phase sensitivity can be achieved in the OCMI system by employing micromachining methods.


Electrical and Computer Engineering

Research Center/Lab(s)

Intelligent Systems Center

Keywords and Phrases

Fiber Optic Sensors; Fiber Optics; Fs-Laser Micromachining; Interferometry; Laser Beams; Microwave Amplifiers; Microwave Photonics; Optical Fiber Amplifiers; Optical Fiber Sensors; Optical Fibers; Optical Interferometry; Phase Shift Amplification; Sensitivity

International Standard Serial Number (ISSN)

1077-260X; 1558-4542

Document Type

Article - Journal

Document Version


File Type





© 2021 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

Nov.-Dec 2021