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Wuxi, China

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).


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.


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. | 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).


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.

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