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

Optics Letters (Impact Factor: 3.29). 10/2012; 37(20):4263-5. DOI: 10.1364/OL.37.004263
Source: PubMed


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.

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Available from: Sung-Liang Chen, May 01, 2014
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    • "form with a raster scan of the laser beam performed by a microelectro-mechanical-systems (MEMS) mirror, which is used to meet the requirement of system miniaturization [84]. The system is capable of 3D imaging with high resolutions of 17.5 μm in lateral direction and 20 μm in axial direction. "
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    ABSTRACT: Development of both fundamental research and clinical applications of photo acoustic imaging call for ultrasound detectors of high sensitivity, flat frequency response and compact size, which are not easily satisfied by traditional ultrasound detectors. Therefore, many alternative ultrasound detectors have been investigated in recent years and are presentative one is the imprinted polymer microring resonator based detector. This review covers its principle, device fabrication, characterization and application, with an emphasis on how the microring’sunique properties make it actas a high performance ultrasound detector in photo acoustic imaging systems. The imprinted polymer microring has high detection sensitivity, broadband frequency response, compact size and good operation robustness. Application of microrings in photo acoustic tomography generates truthful reconstructed images; use of microring in photo acoustic microscopy leads to improved image resolution; the detector’scompact sizemakes it promising for photo acoustic endoscopic applications. When integrated with other electromagnetic wave absorbers, novel applications such as real-time terahertz pulse detection can be realized.
    Journal of Lightwave Technology 08/2015; DOI:10.1109/JLT.2015.2466661 · 2.97 Impact Factor
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    • "The maximum angular deflections are AE68 and AE98, resulting in a large field-of-view of 1.29 mm  1.95 mm considering the 6.16 mm focal length of the objective lens. More details of the MEMS mirror used in this work can be found in our previous work [27]. Due to the 50 Hz limit of the MEMS driver board, a 2D raster scan of 256  256 steps takes almost half an hour, which also includes the data transfer time. "
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    Photoacoustics 05/2013; 1(2):30–35. DOI:10.1016/j.pacs.2013.07.001 · 4.60 Impact Factor
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    ABSTRACT: A four dimensional data set of the cardiac cycle of a zebrafish embryo was acquired using postacquisition synchronization of real time photoacoustic b-scans. Utilizing an off-axis photoacoustic microscopy (OA-PAM) setup, we have expanded upon our previous work with OA-PAM to develop a system that can sustain 100 kHz line rates while demodulating the bipolar photoacoustic signal in real-time. Real-time processing was accomplished by quadrature demodulation on a Field Programmable Gate Array (FPGA) in line with the signal digitizer. Simulated data acquisition verified the system is capable of real-time processing up to a line rate of 1 MHz. Galvanometer-scanning of the excitation laser inside the focus of the ultrasonic transducer enables real data acquisition of a 200 by 200 by 200 pixel, volumetric data set across a 2 millimeter field of view at a rate of 2.5 Hz.
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