Wuxi, China
Wuxi, China

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Wang D.,Shanghai Key Laboratory of Modern Optical Systems | Wang D.,WiO Technology Ltd. | Fu L.,WiO Technology Ltd. | Wang X.,Nanjing Medical University | And 6 more authors.
Journal of Biomedical Optics | Year: 2013

A microelectromechanical system (MEMS) mirror based endoscopic swept-source optical coherence tomography (SS-OCT) system that can perform three-dimensional (3-D) imaging at high speed is reported. The key component enabling 3-D endoscopic imaging is a two-axis MEMS scanning mirror which has a 0.8 × 0.8 mm2mirror plate and a 1.6 × 1.4 mm 2 device footprint. The diameter of the endoscopic probe is only 3.5 mm. The imaging rate of the SS-OCT system is 50 frames/s. OCT images of both human suspicious oral leukoplakia tissue and normal buccal mucosa were taken in vivo and compared. The OCT imaging result agrees well with the histopathological analysis. © 2013 Society of Photo-Optical Instrumentation Engineers.


Duan C.,University of Florida | Wang W.,University of Florida | Zhang X.,University of Florida | Ding J.,WiO Technology Ltd. | And 3 more authors.
Proceedings of the IEEE International Conference on Micro Electro Mechanical Systems (MEMS) | Year: 2015

This paper presents a 2-axis electrothermal single-crystal-silicon (SCS) micromirror that is tilted 45° out of plane on a silicon optical bench (SiOB). The SiOB provides mechanical support and electrical wiring to the tilted 2-axis mirror as well as an aligned trench for assembling other optical components such as optical fibers. The tilt of the mirror is achieved with the bending of a set of stressed bimorph beams and the stop is provided by the silicon sidewall. The tilt angle can be precisely controlled by properly choosing the distance from the mirror frame to the silicon sidewall and the flexure bimorph length. The mirror plate is 0.72 mm × 0.72 mm and the footprint of the entire MEMS device is 2.22 mm × 1.25 mm. The measured maximum optical scan angles of the mirror are 40.0° in both x- and y-axis. © 2015 IEEE.


Duan C.,University of Florida | Zhang X.,University of Florida | Wang D.,University of Shanghai for Science and Technology | Wang D.,WiO Technology Ltd. | And 4 more authors.
2014 IEEE 11th International Symposium on Biomedical Imaging, ISBI 2014 | Year: 2014

A two-axis scanning MEMS based forward-viewing endoscopic imaging probe has been developed and successfully applied in a swept source OCT system for three-dimensional imaging. The 2-axis MEMS mirror has an aperture size of 0.85 mm by 0.85 mm and a chip size of 1.5 mm by 1.7 mm and the outer diameter of the probe is 5.0 mm. The MEMS mirror achieves large optical scan angle up to 30° at 3 V. The MEMS based forward-imaging probe demonstrates real time 3D OCT images of human nail and rat skin with 10.6 um axial resolution and 17.5 um lateral resolution at a frame rate of 50 fps. © 2014 IEEE.


Wang D.,University of Shanghai for Science and Technology | Wang D.,WiO Technology Ltd. | Liang P.,WiO Technology Ltd. | Samuelson S.,University of Florida | And 3 more authors.
Biomedical Optics Express | Year: 2013

A two-axis scanning microelectromechanical (MEMS) mirror enables an optical coherence tomography (OCT) system to perform threedimensional endoscopic imaging due to its fast scan speed and small size. However, the radial scan from the MEMS mirror causes various distortions in OCT images, namely spherical, fan-shaped and keystone distortions. In this paper, a new method is proposed to correct all of three distortions presented in OCT systems based on two-axis MEMS scanning mirrors. The spherical distortion is corrected first by directly manipulating the original spectral interferograms in the phase domain, followed by Fourier transform and three-dimensional geometrical transformation for correcting the other two types of distortions. OCT imaging experiments on a paper with square ink printed arrays and a glass tube filled with milk have been used to validate the proposed method. Distortions in OCT images of flat or curved surfaces can all be effectively removed. © 2013 Optical Society of America.


Duan C.,University of Florida | Wang D.,University of Shanghai for Science and Technology | Wang D.,WiO Technology Ltd. | Zhou Z.,WiO Technology Ltd. | And 4 more authors.
Progress in Biomedical Optics and Imaging - Proceedings of SPIE | Year: 2013

A MEMS-based common-path endoscopic imaging probe for 3D swept-source optical coherence tomography (SSOCT) has been developed. The common path is achieved by setting the reference plane at the rear surface of the GRIN lens inside the probe. MEMS devices have the advantages of low cost, small size and fast speed, which are suitable for miniaturizing endoscopic probes. The aperture size of the two-axis MEMS mirror employed in this endoscopic probe is 1 mm by 1 mm and the footprint of the MEMS chip is 1.55 mm by 1.7 mm. The MEMS mirror achieves large two dimensional optical scan angles up to 34° at 4.0 V. The endoscopic probe using the MEMS mirror as the scan engine is only 4.0 mm in diameter. Additionally, an optimum length of the GRIN lens is established to remove the artifacts in the SSOCT images generated from the multiple interfaces inside the endoscopic imaging probe. The MEMS based commonpath probe demonstrates real time 3D OCT images of human finger with 10.6 μm axial resolution, 17.5 μm lateral resolution and 1.0 mm depth range at a frame rate of 50 frames per second.


Wang D.,University of Shanghai for Science and Technology | Wang D.,WiO Technology Ltd. | Fu L.,WiO Technology Ltd. | Sun J.,University of Florida | And 3 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

Optical coherence tomography (OCT) provides non-invasive cross-sectional imaging capability and high resolution, but it has very limited applications inside human body because of the stringent size requirements for accessing the internal organs. Micro-Electro-Mechanical Systems (MEMS) is an emerging technology that can make devices with small size and fast speed. This paper reports the design optimization of a MEMS mirror-based miniature OCT probe. The probe consists of three main parts: a GRIN lens module (1.3 mm in diameter), a MEMS mirror (1.7 mm x 1.55 mm), and a stainless steel mount. A special assembly holder is designed for easy placement of parts and accurate optical alignment and real-time monitoring of optical alignment and electrical characteristics is also used to the assembly process. Code V is used for the optical design and analysis. Simulation shows that the changes of the spot size and focal length are within the acceptable range when the distance between the optical fiber and the GRIN lens varies less than 0.1 mm. The fiber may tilt as much as 2.5 degrees without any considerable change of the spot size and working distance. The maximum tolerance to the lateral shift between the fiber and GRIN lens is about 0.1 mm. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).


Donglin W.,Zhengzhou University of Light Industry | Kun Y.,Zhengzhou University of Light Industry | Yin Z.,WiO Technology Ltd.
Applied Optics | Year: 2016

Measuring the refractive index and volume of liquid under high pressure simultaneously is a big challenge. This paper proposed an alternative solution by combing optical coherence tomography with microscopy. An experiment for a feasibility study was carried out on polydimethylsiloxane liquid in a diamond anvil cell. The refractive index of the sample increased dramatically with pressure loaded, and the curve of pressure volume was also obtained. © 2016 Optical Society of America.


Liu J.,Soochow University of China | Liu J.,WiO Technology Co. | Xu D.,Soochow University of China | Chen Q.,WiO Technology Co. | And 2 more authors.
Chinese Journal of Sensors and Actuators | Year: 2015

A method of estimating the convection coefficient at microscale is presented in this paper, based on the modeling and experimental data of a microfabricated electrothermal bimorph actuator. In this method, an analytical heat transfer model of the electro-thermal bimorph actuator is established first. Then the model is used to analyze the temperature distribution and extract the convection coefficient from measurement data. The convection coefficient obtained by this method matches the experimental result within 8.1%, which validates the rationality of this method. ©, 2015, The Editorial Office of Chinese Journal of Sensors and Actuators. All right reserved.


Fu L.,WiO Technology Ltd.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

Infrared focal plane detector has a multilayer configuration which consists of substrate, chip, readout IC, Indium interconnects, epoxy and electrical lead board, it is packaged layer by layer precisely. Because of the difference in thermal expansion between the layers, with repeated thermal cycling plenty of thermal stress produced by assembling errors will lead result in failure of the interconnects or lead to damage to the detector pixels. In this paper, based on a detector-Dewar assembly, we analyze the thermal stress on the detector by different packaging accuracy level. With the allowable thermal stress, we optimize the processes of the packaging experiment and redesign the fixtures used in the packaging processes to improve assembly accuracy, on this condition, the detector-Dewar assembly assembled satisfies our design requirement, and the thermal stress caused by the cooler is below the range permitted. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

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