| Optical imaging has been widely used in in the fields of biomedical and material science research with its high resolution. And new optical imaging methods have been emerging, such as optical coherent tomography (OCT), scattering medium imaging based on light field regulation, multi-photon microscopy, fluorescence microscopy, super resolution microscopic imaging. and correlated imaging (also called ghost imaging). In this paper, fiber imaging technology based on the mechanism of turbid media has been studied, which can be used to multi-functional endoscope. Turbid medium imaging technology based on the mechanism of the turbid lens imaging is researched, and fiber imaging in this way has been realized. Moreover, second-order correlated imaging through turbid media imaging and fiber imaging are researched theoretically. In addition, the research on turbid medium as colored relics, crafts, and other aspects of the application of OCT system are carried out. In the end, three kinds of optical fiber temperature sensor with optical fiber multiplexing for imaging have been researched according to the application demand of endoscopic imaging. The specific research contents are as follows:(1) The turbid media imaging based on the mechanism of turbid lens imaging (TLI). First, the principle of turbid lens imaging, transmission matrix extraction method of turbid media, and phase demodulation method based on Hilbert transform have been introduced. And then, a turbid media imaging system has been designed, and a method is proposed for speckle phase extraction method improved from Hilbert transform. Next, a image denoising method for speckle image captured by the camera is specially proposed, which use mean filter combined with a Hanning window filter, can effectively suppress the image noise and retain speckle fringes well. Finally, to verify the transmission matrix extraction experiments of orthogonality and repeatability, and realizing turbid medium imaging experimentally, the resolution is about 5 ?m.(2) Fiber imaging based on the mechanism of turbid lens imaging. Firstly, using multimode fiber as turbid medium, a scheme of fiber imaging based on TLI is proposed, which can be used to endoscope and is realized experimentally with the imaging resolution about 2.2?m. Next, a aperture enhancement method of fiber is proposed, in which the optical fiber is coated with mixture of SiO2 microspheres.(3) Application of optical fiber OCT technology to penetrate turbid media. Based on the 1310 nm band spectral domain optical fiber OCT system, the information of objects hidden in turbid medium was extracted. And then the color painting, ceramics and biological tissue have been detected and analyzed, to obtain the internal structure information of them.(3) Turbid medium imaging and fiber imaging technology based on the mechanism of the correlated imaging have been studied. Firstly, we introduced the basic principle of single arm thermal light correlated imaging, and discussed the contrast, signal-to-noise ratio and resolution performance of correlated imaging, and the corresponding calculation method has been obtained. Then, we designed a correlated imaging system which can penetrate the turbid medium, and it has been researched theoretically. And a simulation calculation have been done by a improved Hadamard matrix to generate illumination pattern. Comparing with the traditional random illumination pattern method, the image quality has been improved significantly in this method. Next, a method of color correlated imaging has been proposed and demonstrated in numerical simulation, and color images are obtained. Finally, a multimode fiber imaging system based on the mechanism of correlated imaging has been proposed, which is suitable for endoscope. The formula and calculation method for its characteristics are presented, and imaging effect has been verified by numerical simulation method.(5) The optical fiber temperature sensing technology based on fluorescence method. Firstly, two kinds of plastic optical fiber temperature sensor based on fluorescence have been designed, which have the error of 0.38? and 0.2?. Then, using the evanescent wave characteristic of photonic crystal fiber within the pores, a fine plastic photonic crystal fiber temperature sensor is designed and which has a error of 0.103?.Researches in this paper are useful to achieve high-resolution imaging, improve the quality of imaging, endoscopic imaging complex temperature sensor. |
PDF Full Text Request