Single Wavelength Strain Sensing Based on Double Taper Mach-Zehnder Interferometer

Abstract

A novel interrogation method is presented in the application of strain sensing with a double taper Mach-Zehnder interferometer (DTMZI). The proposed sensing setup comprises a laser source and an optical power meter, which significantly lowers future integration cost and complexity. An analytical coupling model is established to study the sensor's strain-related modal behaviour. The design parameters of the DTMZI device are conditioned to satisfy a single-wavelength measurement. The spectral responses of several fabricated sensors are examined. Our experiments confirm the direct mapping between different strain values and particular transmission measures for the single wavelength case.

Tension and Torsion Sensing With a Double-Taper Mach-Zehnder Interferometer

“…Given identically fabricated tapers, at wavelength λ, the constructive or destructive interferometry occurs between those modes with a total accumulated differential phase of ±qπ; q is an integer [13]. The total accumulated differential phase for each mode ν can be estimated through the following:…”

“…Moreover, abrupt taper's modeling and its fabrication imperfections have been thoroughly investigated via recent works [9]- [11]. The application of measuring axial strain has been studied on DTMZI, and their modal behaviour has been thoroughly studied [12], [13]. Besides, several reports show the versatility of DTMZI sensors in such applications as refractive index (RI) and temperature sensing [14]- [16].…”