On-chip micro-ring resonator array spectrum detection system based on convex optimization algorithm

Area of Science:

• Photonics
• Optical Engineering
• Signal Processing

Background:

• Traditional spectrum detection systems can be bulky and complex.
• On-chip photonic systems offer miniaturization and integration advantages.
• Micro-ring resonators are versatile components for optical filtering and sensing.

Purpose of the Study:

• To propose and demonstrate an all-on-chip micro-ring resonator array spectrum detection system (MRRAS).
• To achieve fast and high-resolution spectrum reconstruction using convex optimization.
• To develop a compact and CMOS-compatible spectral sensing solution.

Main Methods:

• Utilizing a micro-ring resonator array to construct the system's transmission matrix.
• Applying waveguide transmission theory and convex optimization for spectrum reconstruction.
• Formulating under-determined matrix equations and solving for the least norm solution.

Main Results:

• Demonstrated a functional MRRAS using three micro-ring resonators with a 4 μm radius.
• Achieved a compact footprint and compatibility with silicon nitride photonic platforms and CMOS processes.
• Obtained an operating bandwidth exceeding 12 nm and a spectral resolution better than 0.17 nm.

Conclusions:

• The proposed MRRAS offers a compact, efficient, and high-performance solution for on-chip spectrum detection.
• Convex optimization enables rapid reconstruction of unknown spectra from limited micro-ring resonator outputs.
• The system's CMOS compatibility paves the way for integrated photonic spectral analysis applications.