Side-mode suppressed filter based on anangular grating-subwavelength grating microring resonator with high...

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• Subwavelength grating microring resonators (SWGMRR) are promising for optical sensing and communication.
• Their comb spectrum limits single-wavelength extraction from broadband sources.

Purpose of the Study:

• To propose and demonstrate a novel silicon-photonic side-mode suppressed filter based on angular grating-SWGMRR (AG-SWGMRR).
• To achieve high flexibility in wavelength design for optical sensing and communication applications.

Main Methods:

• Engineered effective index along the inner sidewall of the SWGMRR by arranging silicon pillars of varying widths.
• Investigated impacts of key parameters on center wavelength, side-mode suppressed ratio, and quality factor.
• Simulated bulk sensing application and demonstrated a cascaded system for wavelength multiplexing.

Main Results:

• Achieved high sensitivity of 672.8 nm/RIU and a low limit of detection of 6.69×10⁻⁵ in bulk sensing.
• Demonstrated a cascaded system of six AG-SWGMRRs for wavelength multiplexing by tuning pillar widths.
• The AG-SWGMRR is not restricted by free spectral range for side-mode suppression.

Conclusions:

• The proposed AG-SWGMRR offers excellent performance, compact size, and design flexibility.
• This technology holds significant potential for compact biomedical sensing and advanced optical communication systems.