Research On Correlation Imaging Based On Single Photon Detection

Correlation imaging,also known as ghost imaging,is a new imaging technique emerged in recent years.It has drawn much attention and become the hot topic in the imaging area due to its novel way to retrieve the image of the target.Correlation imaging has a series of advantages as well as features,such as strong ability of anti-noise,high resolution,capability to realize single pixel imaging and weak light imaging and so on.On the basis of the theory and mechanism of correlation imaging,this paper focuses on the research of correlation imaging based on single photon detection.The main contents of this paper are as follows:(1)Research on the basic mechanism of correlation imaging.The intensity model of the thermal light is discussed firstly and the second correlation function is given.Then the imaging schemes basic on quantum light and pseu-dothermal light are talked,especially the lensless correlation imaging with thermal light.Correlation imaging can retrieve the image of the object through the correlation of intensity fluctuation.(2)Computational correlation imaging based on time-correlated single-photon-counting(TCSPC)technique.The detection model of the single photon avalanche diode(SPAD)is discussed firstly and the SPAD can be regarded as a linear device under weak illumination.The basic principle of TCSPC is discussed and we experimentally realized computational imaging under weak illumination with the TCSPC technique.The light was modulated by digital micro-mirror device(DMD)and the SPAD was used to detect the photons.Images under weak illumination were obtained and the result was analyzed.A modified algorithm for correlation is proposed to improve the quality of the result and reduce the imaging time.(3)Research on remote three dimensional correlation imaging based on single photon detection.We first introduce the basic mechanism of three dimensional ghost imaging based laser ranging.We propose the pre-modulated and post-modulated computational scheme for remote three dimensional imaging based on TCSPC.We built the systems and analyze each part of the system in detail.We tested our system outdoors,and finally retrieved high resolution imaging for remote three dimensional objects.