Refractive Index Sensing Using a Three-Port Interferometer and Comparison with Ring Resonators
van Gulik, R.J.J.
de Boer, B.M.
In this paper, we compare ring resonator and three-port Mach-Zehnder Interferometer (MZI) devices fabricated on silicon-on-insulator for the purpose of refractive index sensing. Their respective sensitivities and limits of detection (LOD) were determined with NaCl solutions. A sensitivity of 113.07 nm per refractive index unit (RIU) and LOD of 2.47e-6 RIU was reached for the ring resonators. The most sensitive three-port MZI has a sensitivity of 13051 rad/RIU, and an LOD of 2.76e-8 RIU is shown to be attainable. A three-port MZI combines several advantages of both ring resonators and normal MZI devices, including a constant and scalable sensitivity, high-bandwidth readout, no directional ambiguity, and a simple interrogation setup. Such a device is promising for applications such as pressure, gas, and biosensing.
To reference this document use:
OPT - Optics
TS - Technical Sciences
High Tech Systems & Materials
Three-port Mach-Zehnder interferometer
Silicon on insulator technology
Limits of detection
Refractive index sensing
Refractive index units
Institute of Electrical and Electronics Engineers Inc.
IEEE Journal on Selected Topics in Quantum Electronics, 23 (2)