Mr. Guoqing Wang Profile

Guoqing Wang

at Systems Engineering Research Institute

SPIE Involvement:

Author

Publications (4)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 18 December 2019 Paper

Design of tracking fast-moving target depending on rotating mirror

Guoqing Wang, Jincheng Wang, Lei Ming, Dongliang Wang, Zixuan Fang, Qi Zhao, Jingmin Wang, Dong Chen

Proceedings Volume 11338, 1133838 (2019) https://doi.org/10.1117/12.2547959

KEYWORDS: Mirrors, Cameras, Target detection, Mathematical modeling, Imaging systems, Particles, Signal detection, Sensors, Actuators, Relays

Read Abstract +

Detecting fast-moving particle receives more and more attention both in physics and biology, and the study has shown its significant value either in supersonic speed or in movement of tiny biological particles. A significant amount of preparatory work has already been done to optimize this study. Always using multiple cameras or increasing the distance between detector and target, researchers can obtain favorable results. However, As the application of this technique increases, more and more challenges are emerging. One of the most obvious limitations is that confined space to lay detector. In some sense, rotating mirror can be introduced to make the system compact. It is necessary to analyze how to bring in mirror and built the system. Here, in order to use mirror capturing fast-moving target, we take a piezoelectric actuator to drive mirror, thus adopting a high angular rate to adapt to compact environment. Besides, A series of mathematical formulas and relational model are established to guide the construction of this system. Another advantage of the system, synchronous trigger signal can be triggered by laser and other means wirelessly with high precision. Therefore, having the aid of rotating mirror and wireless trigger, a fast-moving target detection system that has the virtues of no restriction of space is completed. In order to make this system in a successful operation, it is of importance to set up light path under the guidance of theoretical analysis. The experiment of trapping particles can be an effective method to show the system workflow.

Proceedings Article | 24 October 2017 Paper

Design of remote laser-induced fluorescence system's acquisition circuit

Guoqing Wang, Yue Lou, Ran Wang, Debao Yan, Xin Li, Xin Zhao, Dong Chen, Qi Zhao

Proceedings Volume 10461, 104610R (2017) https://doi.org/10.1117/12.2283552

KEYWORDS: Laser induced fluorescence, Laser development, Laser systems engineering

Read Abstract +

Laser-induced fluorescence system(LIfS) has been found its significant application in identifying one kind of substance from another by its properties even it’s thimbleful, and becomes useful in plenty of fields. Many superior works have reported LIfS’ theoretical analysis , designs and uses. However, the usual LIPS is always constructed in labs to detect matter quite closely, for the system using low-power laser as excitation source and charge coupled device (CCD) as detector. Promoting the detectivity of LIfS is of much concern to spread its application. Here, we take a high-energy narrow-pulse laser instead of commonly used continuous wave laser to operate sample, thus we can get strong fluorescent. Besides, photomultiplier (PMT) with high sensitivity is adopted in our system to detect extremely weak fluorescence after a long flight time from the sample to the detector. Another advantage in our system, as the fluorescence collected into spectroscopy, multiple wavelengths of light can be converted to the corresponding electrical signals with the linear array multichannel PMT. Therefore, at the cost of high-powered incentive and high-sensitive detector, a remote LIFS is get. In order to run this system, it is of importance to turn light signal to digital signal which can be processed by computer. The pulse width of fluorescence is deeply associated with excitation laser, at the nanosecond(ns) level, which has a high demand for acquisition circuit. We design an acquisition circuit including, I/V conversion circuit, amplifying circuit and peak-holding circuit. The simulation of circuit shows that peak-holding circuit can be one effective approach to reducing difficulty of acquisition circuit.

Proceedings Article | 24 October 2017 Paper

Study of improving signal-noise ratio for fluorescence channel

Guoqing Wang, Xin Li, Yue Lou, Dong Chen, Xin Zhao, Ran Wang, Debao Yan, Qi Zhao

Proceedings Volume 10461, 104610M (2017) https://doi.org/10.1117/12.2283358

KEYWORDS: Luminescence, Laser induced fluorescence, Laser systems engineering

Read Abstract +

Laser-induced fluorescence(LIFS), which is one of most effective discrimination methods to identify the material at the molecular level by inducing fluorescence spectrum, has been popularized for its fast and accurate probe’s results. According to the research, violet laser or ultraviolet laser is always used as excitation light source. While, There is no atmospheric window for violet laser and ultraviolet laser, causing laser attenuation along its propagation path. What’s worse, as the laser reaching sample, part of the light is reflected. That is, excitation laser really react on sample to produce fluorescence is very poor, leading to weak fluorescence mingled with the background light collected by LIFS’ processing unit, when it used outdoor. In order to spread LIFS to remote probing under the complex background, study of improving signal-noise ratio for fluorescence channel is a meaningful work. Enhancing the fluorescence intensity and inhibiting background light both can improve fluorescence’ signal-noise ratio. In this article, three different approaches of inhibiting background light are discussed to improve the signal-noise ratio of LIFS. The first method is increasing fluorescence excitation area in the proportion of LIFS’ collecting field by expanding laser beam, if the collecting filed is fixed. The second one is changing field angle base to accommodate laser divergence angle. The third one is setting a very narrow gating circuit to control acquisition circuit, which is shortly open only when fluorescence arriving. At some level, these methods all can reduce the background light. But after discussion, the third one is best with adding gating acquisition circuit to acquisition circuit instead of changing light path, which is effective and economic.

Proceedings Article | 15 October 2015 Paper

Calibration of a dual-trap optical tweezers for single molecule force spectroscopy study

Guoqing Wang, Chunguang Hu, Xiaoqing Gao, Chenguang Su, Sirong Wang, Hai Lei, Xiaodong Hu, Hongbin Li, Xiaotang Hu

Proceedings Volume 9672, 96720P (2015) https://doi.org/10.1117/12.2199680

KEYWORDS: Optical tweezers, Calibration, Molecules, Phase modulation, Molecular spectroscopy, Mirrors, Single molecule spectroscopy, Beam splitters, Objectives, Cameras

Read Abstract +

Optical tweezers has shown its significant advantages in applying pico-Newton force on micro beads and handling them with nanometer-level precision, and becomes a powerful tool for single-molecule biology. Many excellent researching results in use of the optical tweezers have been reported. Most of them focus on the single-trap optical tweezers experiments. However, when a single-trap optical tweezers is applied to biological molecule, there is often an obvious noise from the sample chamber holder to which one end of the sample molecule is tethered. In contrast, a dual-trap optical tweezers can intrinsically avoid this problem because both ends of the sample tethered to microspheres are manipulated with two separate optical traps. In order to force the molecule precisely, it is of importance to do calibrations for both traps. Many approaches have been studied to obtain the stiffness and sensitivity of the trap, but those are not quite suitable for making calibration during experiment. Here, we use a modified method of power spectrum density (PSD) for the calibrations of the stiffness and sensitivity of the traps, which combines a sinusoidal motion of the sample stage. The main strength of the method is that the beads used for the calibration also can be used in experiment later. In addition, the calibration can be performed during experiment. Finally, an experiment using a dsDNA molecule to test the system is presented. The results show that the calibration approach for the dual-trap optical tweezers is efficient and accurate.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years