Highly sensitive ultrasound detection using nanofabricated polymer micro-ring resonators.

Area of Science:

• Biomedical Optics
• Photonics
• Medical Imaging

Background:

• Photoacoustic (PA) imaging uses light absorption for noninvasive tissue imaging.
• Conventional piezoelectric ultrasound detectors have limited sensitivity and bandwidth.
• Optical ultrasound detection methods offer improved performance for PA imaging.

Purpose of the Study:

• To review the evolution of polymer micro-ring resonators (MRRs) for ultrasound detection in PA imaging.
• To discuss advancements in MRR design and nanofabrication for enhanced performance.
• To explore novel PA imaging applications enabled by transparent MRRs.

Main Methods:

• Review of polymer MRR design and nanofabrication processes.
• Analysis of MRR performance metrics including sensitivity (NEP) and detection bandwidth.
• Discussion of integrated photonic circuits (IPC) for miniaturized sensing areas.

Main Results:

• Polymer MRRs provide highly sensitive ultrasound detection (0.49 Pa NEP) with a broad frequency range (up to 250 MHz).
• MRRs integrated into IPCs reduce sensing area to 80 μm diameter.
• Transparent MRRs enable multi-modality imaging and advanced PA applications.

Conclusions:

• Polymer MRRs represent a significant advancement in optical ultrasound detection for PA imaging.
• Innovations in MRR design and fabrication enhance sensitivity, bandwidth, and application scope.
• Transparent MRRs pave the way for next-generation PA imaging modalities.