Study on the limit of detection in MZI-based biosensor systems.

Area of Science:

• Integrated photonics
• Photonic sensing
• Optical metrology

Background:

• Mach-Zehnder interferometers (MZIs) are advanced integrated photonic sensors.
• MZIs offer excellent detection limits (down to 10^-7 RIU) and design flexibility.
• Applications include point-of-care diagnostics, leveraging their read-out compatibility.

Purpose of the Study:

• To investigate the interplay between sensor design and noise sources in MZIs.
• To develop a theoretical framework predicting the limit of detection based on noise regimes.
• To provide a guide for optimizing MZI photonic sensor performance.

Main Methods:

• Analysis of three distinct noise regimes: single-arm, dual-arm, and external noise.
• Development of a unified theoretical framework linking noise, sensor design, and detection limits.
• Experimental validation of the theoretical framework using MZI sensors.

Main Results:

• The study quantifies how different noise sources affect MZI sensor design and performance.
• A predictive framework was established, correlating sensor design parameters with the limit of detection.
• Experimental data confirmed the accuracy and validity of the developed theoretical model.

Conclusions:

• The established framework offers a blueprint for optimizing MZI photonic sensor design.
• This optimization is applicable across various read-out methods and measurement conditions.
• The findings facilitate the development of more sensitive and reliable photonic sensors.