Design And Implementation Of A Co-aperture Transceiver Optical System For 3D Laser Image Sensing

In recently years,with the development of unmanned aerial vehicle(UAV),scholars in various countries have paid more and more attention to the 3D imaging sensor technology because of its high resolution and high precision.For the actual needs of the 3D imaging sensor,the thesis presents and designs a new co-aperture transceiver optical system,its core component is an optical isolator which can transmit and receive coaxial.Simultaneously,it not only uses the f-? scanning optical system to solve the low reception power,but also uses the zemax software to design and optimize the optical system for transmitting and receiving.At last,the transceiver optical system is built finished and then verified by experiments.This thesis mainly includes the following aspects:Firstly,aiming at the characteristics of transmitting and receiving optical systems,the thesis analyzes the strength and weaknesses of the system.In view of improving the system coaxiality and reducing the background noise,it also puts forward to design a co-aperture transceiver optical system.Moreover,it compares the types of emission optical systems and studies the laser alignment technique,then derives the basic characteristics of the Gaussian beam and the basic principle of the lens transformation.In order to meet the requirements,appplying the theory of Gaussian beam lens transformation,it uses zemax software to design a two stage beam expanding optical system.Lastly,it analyses spot diagram and aberration of both systems,and achieves the collimator output of 10mm-diameters spot;Secondly,starting from direct detection principle of laser imaging radar,the thesis derives the calculation method of echo power and analyzes the effect of background light noise on the imaging quality.Additionally,it studies the principle for the design and method of the traditional optical isolator,and points out the disadvantage of the power loss caused by the center hole.It tries to design the optical isolation switch,based on not only polarization isolation principle,but also taking advantage of 1/2 and 1/4 wave plate different polarization characteristics.Meanwhile,it constructs the structure of optical isolation switch system,besides studies how to increase the optical signal-to-noise ratio of isolation system.For the characteristics of the receiving optical system,it analyzes the relationship between the APD detector and the receiving field.Another,it designs a set of optical receiving system,meeting the design requirements;Finally,the thesis accomplishes the design of co-aperture transceiver optical system for 3D laser image sensing,meanwhile,it analyzes the advantages of the system in the field of laser imaging radar.Afterwards,it carries out the adjustment and experiment of coaxial optical system for transmitting and receiving,also it tests the polarization isolation system and carries out different target imaging experiments.The expected data is collected in the aspects of both uniform material and complex target imaging,it not only shows that the designed optical system meets the requirements,but also has a good optical isolation effect and near ground target imaging.