Miniaturized all-optical photoacoustic microscopy based on microelectromechanical systems mirror scanning.

Optics Letters (Impact Factor: 3.18). 10/2012; 37(20):4263-5. DOI: 10.1364/OL.37.004263
Source: PubMed

ABSTRACT Achieving photoacoustic microscopic imaging through a miniaturized scanning head is a crucial step toward high-resolution photoacoustic endoscopy. In this work, we have developed a miniaturized probe head using a microelectromechanical systems (MEMS) based mirror for raster scan of the laser beam and our newly developed super broad bandwidth microring resonator based ultrasound detector for photoacoustic signal detection. Through this all-optical design, which offers unique advantages for endoscopic applications, this system is capable of three-dimensional (3D) imaging with high resolution of 17.5 μm in lateral direction and 20 μm in axial direction at a distance of 3.7 mm. After the performance of this system was validated through the experiments on printed grids and a resolution test target, microscopic imaging of the 3D microvasculatures in canine bladders was also conducted successfully, demonstrating the potential of novel photoacoustic endoscopic in future clinical management of bladder cancer.

Download full-text


Available from: Sung-Liang Chen, May 01, 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Detectors play a vital role in ultrasound sensing and imaging applications. With the rapid development of photoacoustic imaging technology in recent years, novel ultrasound detectors based on optical methods have gained increased attention, among which the imprinted polymer microring is a representative one. This review covers the device design, fabrication, and characterization, with an emphasis on how the imprinting-based fabrication methodology benefits the device performance, which further facilitates photoacoustic imaging and sensing applications. By carefully designing and fabricating the imprint mold, the imprinted polymer microring has a quality factor on the order of at 780 nm. The device has advantages such as wide acoustic bandwidth response from dc to 350 MHz at −3 dB, low noise equivalent detectable pressure, wide acceptance angle, and so on. The polymer microring has been successfully employed in applications such as photoacoustic imaging and real-time terahertz pulse detection.
    IEEE Sensors Journal 06/2015; 15(6):3241-3248. DOI:10.1109/JSEN.2015.2421519 · 1.85 Impact Factor
  • IEEE Journal of Selected Topics in Quantum Electronics 07/2015; 21(4):1-1. DOI:10.1109/JSTQE.2015.2389530 · 3.47 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Optical-resolution photoacoustic microscopy (OR-PAM) is a novel label-free microscopic imaging tool to provide in vivo optical absorbing contrasts. Specially, it is crucial to equip a real-time imaging capability without sacrificing high signal-to-noise ratios (SNRs) for identifying and tracking specific diseases in OR-PAM. Herein we demonstrate a 2-axis water-proofing MEMS scanner made of flexible PDMS. This flexible scanner results in a wide scanning range (9 × 4 mm(2) in a transverse plane) and a fast imaging speed (5 B-scan images per second). Further, the MEMS scanner is fabricated in a compact footprint with a size of 15 × 15 × 15 mm(3). More importantly, the scanning ability in water makes the MEMS scanner possible to confocally and simultaneously reflect both ultrasound and laser, and consequently we can maintain high SNRs. The lateral and axial resolutions of the OR-PAM system are 3.6 and 27.7 μm, respectively. We have successfully monitored the flow of carbon particles in vitro with a volumetric display frame rate of 0.14 Hz. Finally, we have successfully obtained in vivo PA images of microvasculatures in a mouse ear. It is expected that our compact and fast OR-PAM system can be significantly useful in both preclinical and clinical applications.
    Scientific Reports 01/2015; 5:7932. DOI:10.1038/srep07932 · 5.08 Impact Factor