| Thermonuclear fusion produces enormous energy,the indirect of ICF drive research plays a very important role and great potential appalications in the energy,military,defense,etc.In the laser generates heat fusion process,the laser-quality diagnostic and measured parameters is very important.scientific grade CCD as a sophisticated diagnostic devices,with low noise,wide dynamic range and other characteristics,are widely applicable to conventional diagnosis of the laser beam in the near and far field of the distribution of the laser beam.Focal spot distribution and other parameter,provide a variety of support parameters for laser targeting,achieve to beam diagnostics before targeting and get information after targeting.In this paper,we mast the key points of the scientific grade CCD camera in the process of research and development based on study of scientific grade CCD camera,to establish a system of camera research and development and measurement.And based on these above,developed a low noise,wide dynamic range of camera imaging system,can be applied to the measurement of laser parameters,and through the experimental data acquisition research and analysis on the scientific grade CCD camera noise,and through some method on how to increase the camera dynamic range,to further improve the performance parameters of the camera.In the other hand,we also research on new application of camera and method of laser parameters measurement.1)On the base of study in several scientific grade CCD and the fields of using,the hardware selection of the camera,the noise simulation,the PCB board design and the debugging work of the camera are completed,designed and developed a UDP-based Gigabit Ethernet protocols from scientific-grade CCD camera.2)In the measurement for the scientific grade CCD index calibration,design a measurement system for the CCD which used in parameters measurement of strong laser,the system consists of 1053 nm laser,integrating sphere,signal generators,as well as the computer used for data acquisition and calculations show and control software,a new method is reported use image of wedge interference by camera and intensity distribution of laser Interference by calculate,finally obtain the photoelectric response characteristics of the camera through data processing.This method not only ensures the calibration results,but also simple and fast,provides a basis for get accurate data of ICF experiments.The system can automatically acquisit image data and calculate indicators,can quickly complete large quantities of camera accurate calibration work.3)To analyze the influences resulted by CCD noise in laser near field distribution measurement,3-D noise model was used to analyze the characters of CCD noise which was classified into spatial noise and temporal noise.Spatial noise was used to evaluate influences resulted by no-uniformity between different pixels and temporal noise was used to evaluate influences resulted by multiple measurements.By testing for one type of CCD,it was shows that noise were signal-dependent terms and followed normal distribution.The experiments verified that this model was effective.The method is used in and proved more effective.4)According to the three-dimensional noise model of the scientific CCD,proposed proper noise reduction methods for the two different noises(i.e.temporal noise and special noise).for temporal noise,it is associated with the signal,using the method proposed non-sampling discrete wavelet transform noise reduction,compared this method with LMS and The median filter,through theoretical calculations and experimental results show that the wavelet algorithm has a good noise removal effect.On the other hand,The reason of non-uniformity(PRNU)of image sensor's photo response are analyzed,it is concluded in two faces,one caused by spatial noise which and another caused by temporal noise,theses two influence the CCD gravely.In the method of erase non-uniformity of CCD,the calibration accuracy declines when there is relative location change between the camera and the integrating sphere in the process of non-uniformity calibration.A new method of relative radiometric calibration using multi-position fused data was proposed.To eliminate the shortcoming of angular and facial non-uniformity of the integrating sphere,the calibration coefficients were obtained by a lot of images from multi-positions.Experiment results show that the proposed method can decrease the effect of non-uniformity of the sphere light intensity on the calibration coefficients.5)A new method of laser measurement with scientific grade CCD camera is proposed to back up energy measured,and explore camera laser pulse energy measurement principles,protocols,error analysis and calibration laboratories.Through the acquisition and analysis of experimental data show that the method can be achieved CCD laser energy measurement and laser near-field distribution measurement,by the experimental method error of measurement the is analyzed.On the other hand,A method of measure the high dynamic range laser focal spot was proposed and successful application in the engineering of a high dynamic range laser focal spot measurement schlieren method,use of alignment system make the schlieren balls covered in sidelobe facula center,then accurate get spot information,for the first time in large laser schlieren method is used to realize the strong laser focal spot far field measurement by data refactoring,it shows that the focal spot were obtained by schlieren method and reconstruction in the process of all kinds of optimization,is able to achieve large dynamic range of focal spot measurement. |
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