Based On The OAM Transceiver Technology In Orthogonal Modulation And Demodulation

With the rapid development of optical communication,we are not satisfied with the current spectrum resource.Consequently more and more people are exploring a completely new transmission carrier whichcan enhance the transmission density to the next level.During the research on the Orbital angular momentum(OAM)in recent years,it's been proved that it can be used on the control of photon and the process of quantum information and image.Besides,the advantage on transmission capacity is remarkable as well.This dissertation discusses variety of generation and detection methods of OAM and makes a comparison of the historical developments on the different detection methods under different situationsThe main contents contain:Starting with the distinct generation and detection methods of OAM,this dissertation conducts a detailed exploration on the generation of OAM such as spiral phase plate(SPP),Mode conversion and computer generated holograms(CGHs)and the detection of OAM including laser interferometer,Hologram and Coordinate transformation separately.The research is based on the different of generation and detection of OAM on the implementation principles,construction methods,and theory deductions and the comparison is made on the performance among various methods.Construct new orthogonal modulation by combining various factors such as frequency,amplitude and phase and analyzing and using different parameters of optical signal.Analyze the reception and demodulation problems of the orthogonal modulation.Describe the current flow when modulation occurs based on the three principles as APol,16QAM and CSRZ_FSK.Compare the two ways of FSK demodulation.Make a comparison of two applications of OAM with the traditional orthogonal modulation.Analyze coding with OAM(OAM Keying);Describe two ways for OAM to transmit information by considering the OAM as carrier.Emulate Laguerre-Gaussian beam in an experiment environment according to the multiplexing modulation of OAM.Achieve the generation of OAM with integer topological charge(TC).Build the orthogonal modulation on the information link by the multiplexing of constructed OAM with different TC and the APol.Obtain the carried information on OAM corresponding with every TC by means of orthogonal demodulation of OAM on the receiver.Describe the modulation information on every channel according to the bit error rate.Design a method to obtain the OAM beam with non-integral TC based on the OAM with integral TC.Realize the loading of OAM beam information on the basis of the description of unconventional generation method of OAM.Explore the effects on the system from the compositional index and Gouy phases under such situation.Complete the multiplexing transmission and demodulation of the information from two different fraction order of OAM.The result of simulation indicates the rate and capacity can be improved comprehensively on the optical communication link by utilizing the completely flexible modulation method of OAM.