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Updated: Jun 9, 2026

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Three-dimensional Optical-resolution Photoacoustic Microscopy
Published on: May 3, 2011
Imprinted high-Q polymer micro-ring resonator array for high-resolution photoacoustic tomography
Hyeonwoo Kim1, Wei-Kuan Lin1, Linyu Ni2
1Department of Electrical Engineering and Computer Sciences, University of Michigan, Ann Arbor 48109, USA.
Summary
Researchers developed a polymer micro-ring resonator array using nanoimprint lithography for photoacoustic tomography (PAT). This advanced imaging technique achieved high resolution, enabling differentiation of prostate cancers from normal tissues.
Area of Science:
- Photonics and Biomedical Imaging
- Materials Science and Nanofabrication
Background:
- Micro-ring resonators are crucial optical components with tunable resonance properties.
- Photoacoustic tomography (PAT) offers high-resolution imaging of biological tissues.
- Nanoimprint lithography (NIL) enables precise fabrication of nanostructures.
Purpose of the Study:
- To demonstrate a polymer-based micro-ring resonator array for enhanced photoacoustic tomography (PAT).
- To achieve high-resolution biomedical imaging and differentiate tissue types using spectral analysis.
Main Methods:
- Fabrication of a polymer micro-ring resonator array (>40 elements) using nanoimprint lithography (NIL).
- Precise control of micro-ring radii for distinct resonances within a narrow free spectral range (2.19 nm).
- Application of the array for PAT imaging of ex vivo mouse prostates.
Main Results:
- Achieved lateral and axial resolutions of 40 μm and 38 μm, respectively.
- Obtained an ultrasound response bandwidth of 173.5 MHz and a noise equivalent pressure (NEP) of 13.5 Pa.
- Demonstrated high correlation of PAT images with biological tissue structures and blood vessels, differentiating prostate cancers.
Conclusions:
- NIL-fabricated polymer micro-ring resonator arrays offer significant advantages for biomedical imaging.
- The developed system shows potential for advanced optical communications and integrated photonic systems.
- Spectral analysis of PAT data enables accurate differentiation of cancerous and normal prostate tissues.

