Photonic Biosensor in Young Interferometer Configuration*

In this research, we present the development and characterization of a highly sensitive

photonic biosensor based on the Young interferometer configuration. The sensor leverages

the principles of photonic waveguides and interference to achieve precise measurements

of biomolecular interactions.

The core of our biosensor consists of a 54 nm thick Si3N4waveguide, optimized for single-

mode operation in air. This waveguide exhibits excellent sensitivity due to its enhanced

interaction with the surrounding medium. We demonstrated bulk sensing measurements

using glucose solutions of varying concentrations, with the sensor producing high-quality

interference fringes in the output. The visibility of these fringes, defined as

( I_max-I_min)/ (I_max+I_min) exceeded 0.75 in all experiments, indicating high signal clarity and low

noise.

Our photonic chip's ability to produce clear and consistent fringes allows for accurate

phase estimation from the fitted interference patterns. The low error in phase estimation is

attributed to the superior fringe visibility and reduced interference noise. This research

highlights the potential of photonic waveguide-based biosensors in achieving high

sensitivity and specificity for various biochemical sensing applications.

The results demonstrate that our photonic biosensor can serve as a powerful tool for real-

time monitoring of biomolecular interactions, offering significant advantages in fields such

as medical diagnostics, environmental monitoring, and industrial process control.