Design of Directional Coupler Structure in Electro-Optic Integrated Circuit Using Refractive Index Sensor Based on Silicon Nitride Substrate

Subject Areas : Journal of Optoelectronical Nanostructures

Sina Tahanazadeh ¹ , Sharifeh Shahi ² , Atefeh Salimi Shahraki ³

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Received: 2025-02-01 Accepted : 2025-08-20 Published : 2025-11-30

Keywords: Directional Coupler Waveguide, Fundamental Mode , Photonic Integrated Circuit (PIC), Refractive Index, Sensor,

Abstract :

Predicting various conditions is paramount in today's world, and sensors embedded within electro-optical integrated circuits play a vital role in fulfilling this critical need. Ansys Lumerical software, with its powerful MODE and FDTD modules, emerges as an indispensable tool for analyzing light behavior within intricate structures and evaluating their feasibility for future applications. The MODE module, equipped with the FDE and varFDTD solvers, excels in efficiently simulating light propagation, providing rapid results that are invaluable for initial comparisons and design exploration.

This efficiency is particularly advantageous when contrasted with the more precise but computationally demanding FDTD module. In this study, a simulated sensor was strategically integrated into a directional coupler structure. By meticulously analyzing light propagation through strategically placed monitors within this integrated system, the researchers were able to gain valuable insights into the sensor's performance. The findings unequivocally demonstrated that the varFDTD solver within the MODE module proved highly effective in optimizing the design of the directional coupler. This optimization resulted in a significant enhancement of the sensor's efficiency, ensuring its robust and reliable operation across a wide range of environmental conditions and operational scenarios.

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