Research On Electronic Control And Image Acquisition Systems Of Picosecond Optical Framing Imager

There are many objects with high-speed movement and transient phenomena in daily life. Due to human being eye’s persistence of vision, the detailed process could not be seen clearly. In order to extend the eye’s distinguishing ability, people have been working hard on exploring a variety of high-speed imaging technologies. A high-speed imager can record the transient states or time history for ultra fast events, which is almost the only effective tool to obtain time and space information of transient objects, and gives a great help for visually studying generation mechanism and change rules of transient processes. Therefore, it has important applications in natural sciences, engineering technology and many other fields.High-speed imaging technologies with different time resolutions are required for researching transient processes with different speeds. Such as the research on ultra high-speed process of detonation, explosion and shock wave needs microsecond(10-6s) time resolution; and the research on ultra short laser pulses, laser fusion, photon biochemical processes and etc. requires nanosecond(10-9s) time resolution. For visually researching other shorter varying processes, imaging technology with higher time resolution is needed. Such as the research for growth and decay process of plasma in gas and solids needs picosecond(10-12s) time resolution.Topic basis of this thesis is from a project about a picosecond optical framing imager(POFI), which is an extremely high-speed imaging equipment with picoseconds time resolution, and can record multiple digital images. This equipment is composed by optical source system, framing system, optical imaging system, electric control system and image acquisition system. The main task of this thesis is to research and design the image acquisition system and electric control system of the POFI, and then to conduct the principle experiment based on above-mentioned designs. The main content of this thesis is as below:(1) It introduces the structure, components and operating principle of the POFI.(2) It states scheme of electric control and digital images acquisition of the POFI. An image acquisition software has been developed with functions of image acquisition, transmission, storage and display, which can meet the requirement for 16-channel CCD cameras to get images in the POFI.(3) Based on a STC89C52 MCU and analog delay chips, a multi-channel programmable pulse delay generator has been designed. Single triggering pulse and control signals for multiple CCD cameras have been implemented with a FPGA device. Based on this, the electric control system of the POFI has been built, which can realize synchronous control for related components of the POFI.(4) Experiments for verifying principle of the image acquisition system and the electric control system have been conducted, in which a laser beam was deflected at high speed by a rotating mirror and imported to the framing system of the POFI, and 16 digital images of a moving target were obtained with the image acquisition system, which verified feasibility of the designs.