Photonic molecules for application in silicon-on-insulator optical sensors

Author(s)

Barea, Luis A. M. ; Souza, Mario C. M. M. ; Moras, Andre L. ; Catellan, Alvaro R. G. ; Cirino, Giuseppe A. ; Von Zuben, Antonio A. G. ; Bassani, Jose W. M. ; Frateschi, Newton C. ; Reed, GT ; Knights, AP

• Document type: Journal article
• Source: SILICON PHOTONICS XIII; v. 10537, p. 8-pg., 2018-01-01.

Abstract

Optical sensors based on integrated photonics have experienced impressive advancements in the past few decades and represent one of the main sensing solutions in many areas including environmental sensing and medical diagnostics. In this context, optical microcavities are extensively employed as refractive index (RI) sensors, providing sharp optical resonances that allow the detection of very small variations in the surrounding RI. With increased sensitivity, however, the device is subjected to environmental perturbations that can also change the RI, such as temperature variations, and therefore compromise their reliability. In this work, we present the concept and experimental realization of a photonic sensor based on coupled microcavities or Photonic Molecules (PM) in which only one cavity is exposed to the sensing solution, allowing a differential measurement of the RI change. The device consists of an exposed 5-mu m radius microdisk resonator coupled to an external clad microring resonator fabricated on silicon-on-insulator (SOl) platform. This design allows good sensitivity (26 nm/RIU) for transverse electrical mode (TE-mode) in a compact footprint (40 x 40 mu m(2)), representing a good solution for real-life applications in which measurement conditions are not easily controllable. (AU)

• FAPESP's process: 15/12461-8 - Optical sensors based on photonic molecules fabricated on Silicon-on-insulator platform
• Grantee: Alvaro Ricardo Guiato Catellan
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 14/04748-2 - Coupled microresonators applied to signal processing and photonics integration
• Grantee: Mário César Mendes Machado de Souza
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 15/20525-6 - Active devices exploiting capacitively-inducedc free-carrier effects in silicon waveguides
• Grantee: Mário César Mendes Machado de Souza
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate