Acousto-optic tunable filters (AOTF) are widely used in hyperspectral imaging systems as filtering devices. It has the advantages of stable structure, fast tuning and high portability. This paper report the tuning of AOTF by controlling the incident angle and obtains the relationship between the angle of the incident light and the wavelength of the diffracted light. The characteristic of angular spectrum selection of AOTF was demonstrated experimentally. A spatial filter system of acousto-optic method is designed by combining AOTF and Fourier lens. The functions which enhance imaging contrast of the system are completed by a single AOTF device. Using this system the edge enhanced image of resolution target was acquired. Different from using a diaphragm for spatial filtering, this filtering method based on acousto-optic effects is continuously adjustable, real-time and stable, and provides a new idea for enhancing the contrast of optical images.
Endoscopic imaging systems are widely used in non-invasive diagnosis of internal tissues in biomedical applications. The imaging clarity and resolution of current fiber-optic endoscopes is far less than that of electronic endoscopes. However, the electronic endoscope has the loss of information related to the principle of the three primary colors of image transmission, which makes the color reproduction ability poor. In order to solve this problem, this paper proposes a hyperspectral imaging system that combines acousto-optic tunable filter (AOTF) and fiber endoscope. The system can obtain images at any wavelengths and obtain spectral information of samples. The system eliminates the loss of information related to the three-color principle. In this paper, firstly, a hyperspectral imaging system based on fiber endoscope is designed, then we test the performance of the system by imaging the resolution target, and finally evaluates the imaging and spectral resolution of the system. The experimental results show that the hyperspectral imaging system based on fiber endoscope has greater advantages than a single fiber endoscope system. The imaging resolution and image contrast of the system have been further improved, and the spectral bandwidth is about several nanometers. Any filtering center wavelength in the visible light range can be quickly selected through random access or continuous tuning, which provides more auxiliary information and convenience for medical diagnosis. The additional spectral information increases the reliability of medical diagnosis based on the data provided by the fiber endoscope.
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.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
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.