Research On Background Light Elimination Based On ATP

As a kind of wireless broadband communication model，optical communicationoccupies a more and more important role in modern communication, has a broadapplication prospect. How to improve the accuracy of acquisition, pointing, trackingsystem(ATP) to adjust the beam is very important. Position sensitive detector (PSD)as the error detection device to improve the accuracy of ATP system, affect theaccuracy of ATP system. From the analysis, to improve the accuracy of PSD, the mostimportant thing is to inhibit the background light which would interfere PSD’s work.Surface plasmon polaritons is a kind of non-radioactive electromagnetic waves inhybrid state,which is restricted along the surface by the collision of the metal after theoscillation of free electrons of the metal surface with the incident photon.During thisprocess, free electrons only couple with the same resonant frequency of the incidentradiation light wave,and absorb most of the energy of incident light, this wavelengthselectivity can be used in the production of spectroscopic device.Firstly, This paper introduces the principle of laser communication, Describes thebasic theory of ATP and PSD system, analyzes the type classification of backgroundlight and relevant light elimination methods. introduces the meaning of subject,narrating the history of SPPs and current development of related applications,thandescribes theory of the finite difference time domain analysis(FDTD),which is widelyused in the field distribution simulation.Second,based on the evanescent wave theory, the paper gives comprehensivedescription of the basic theory of surface Plasmon, and studies the model ofmetal,dispersion relations and basic parameters, then introduces the principle ofexcitation and related properties.Finally, studies the triggering mechanism of Kretschmann structure. From thereflectance equation, analyses the effect of different excitation angles, choice ofmaterials and the thickness of metal film and other parameters on the excitation ofPSD. Then, sums up the influence of each parameter, and uses Matlab to search optimal combination of parameters of each wavelength.According to combinations of the parameters, uses Optic FDTD software tosimulate Kretschmann structure element, and proves the correctness of the excitationprocess parameters. Then,designs series connecting and single series connectingfilter channel based on the principle of light splitting,simulating the filteringperformance and analyses. Then we analyzes the advantages and disadvantages ofeach spectral performance and compares the two devices. At last, gives the analysisof the problems in the simulation.