Integrated refractive index sensor based on an AlN-PSiO₂ hybrid plasmonic microdisk resonator

Area of Science:

• Photonics and optical sensing
• Materials science for optoelectronics
• Nanophotonics and plasmonics

Background:

• Microdisk resonators (MDRs) are crucial optical devices.
• Hybrid plasmonic waveguides (HPWs) offer enhanced light confinement.
• Aluminum Nitride (AlN) and Silicon Dioxide (SiO2) are key materials in integrated optics.

Purpose of the Study:

• To investigate the refractive index (RI) sensing characteristics of an AlN-SiO2 HPW-based MDR (APHPW-MDR).
• To optimize the structure of the APHPW-MDR for improved plasmonic performance.
• To evaluate the potential of the APHPW-MDR in biochemical sensing and integrated optical devices.

Main Methods:

• Utilizing the finite element method (FEM) to study plasmonic characteristics in near-infrared wavelengths.
• Performing structure parameter optimizations to enhance propagation length.
• Simulating quality factor (Q), extinction rate (ER), and RI sensing sensitivity (S).

Main Results:

• Achieved a propagation length (L) of ~165µm, 2.5 times longer than AlN HPW-MDR.
• Obtained a quality factor (Q) of ~621.3 and an extinction rate (ER) of ~30dB.
• Demonstrated a high RI sensing sensitivity (S) of ~276.6 nm/RIU.

Conclusions:

• The APHPW-MDR exhibits significantly improved propagation length and plasmonic performance.
• The developed RI sensor shows great promise for high-performance biochemical sensing.
• Potential applications include integrated optical filters, modulators, switches, routers, and delay circuits.