Integrated Optical Sensors Based on Photonic Molecules with Light Propagating in Clockwise and Counterclockwise Directions

• Grant number: 24/17059-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Luis Alberto Mijam Barea
• Grantee: Laila Pereira El Haddad
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Photonic Molecules (PMs) based on multiple coupled microcavities are being employed in various applications, from telecommunications to optical sensors. Although their unique properties offer excellent improvements for the applications that use them, in the context of optical sensors, the need to sweep the wavelength and monitor the output spectrum for sensing purposes creates a bottleneck in terms of minimizing implementation costs. In this regard, this research project proposes to study possible solutions to ensure a variation in the output power of a PM as changes in the refractive index occur within an open detection window over the PM. However, the main goal is to achieve this variation in the PM's output power using a laser centered on a single wavelength. To this end, a methodology is proposed to investigate the spectral response of a PM that allows for interference between light traveling through its internal rings in clockwise and counterclockwise directions, with and without the integration of a U-shaped feedback waveguide. The light interference paths within the PM, in the presence of the detection window and the feedback guide, should be influenced by changes in the refractive index at the detection window, avoiding spectral shifts common to PMs but resulting in significant reductions in their extinction ratio. This efficiently designed characteristic should ensure monitoring solutions based on the change in output power of the PM with pumping at a single wavelength, centered on these 'locked' resonances in the spectrum. Additionally, this work also proposes to conduct a study on the available micro and nano fabrication methods in partner laboratories, as well as the generation of virtual masks for the future fabrication of the designed sensor, enhancing the development of human resources with experience in this technologically relevant and growing field in Brazil