Optical antennas play the role of transmitting and receiving coupled optical signals in optical wireless communication,and a pair of multipoint transmitting antennas can expand optical wireless communication applications.Summarize the development of one-to-multipoint optical antennas at home and abroad,and introduces the basic prin-ciples of optical fiber array structure,three-concentric sphere structure and rotating paraboloid one-to-multipoint opti-cal antenna.Finally,the development prospects of this field are foreseen.Optical wireless communication is an emer-ging communication technology with advantages of high speed,large capacity and good security.However,the tradi-tional optical wireless communication system has the limitation of single-to-single communication mode,which can't satisfy the demand of multi-user simultaneous communication.Optical antenna plays the role of transmitting and re-ceiving coupled optical signals in optical wireless communication,and a pair of multipoint transmitting antennas can expand the applications of optical wireless communication.The development of one-to-multipoint optical antennas at home and abroad is summarized,and the basic principle of one-to-multipoint optical antennas is introduced.Several existing one-to-multipoint optical antennas design schemes are discussed.Finally,the development trend of this field and the future development direction are prospected.
The working performance of an optical communication system is not only related to the light source,but als-o to its transmission medium.With the development of fiber optic technology and the pursuit of longdistance trans-mission in the field of optical communication,optical amplifiers have emerged.Optical amplifiers can directly amplify optical signals and have great application value in the field of communication.Summarized the basic p-rinciples and development of optical amplifiers.Firstly,the concept,classificaee types of optical amplifiers were introduced,inclu-ding their working princ-iples and performance.Then,the current situation of various types of optical amplifiers at home and abroad was analyzed.Finally,the future development of optiction,and principle of optical amplifiers are in-troduced.Then,the key technologies of the thral amplifiers is prospected.
The theory of compressed sensing shows that the original signal can be recovered by low sampling rate,so it is often used in the field of optical imaging.In order to solve the problem of large amount of data and heavy com-putational burden when compressed sensing is used to reconstruct images,a blocking compressed sensing method is proposed.In this paper,we propose the compressed sensing methods of column block and mixed blocking.The block by column mode reduces the requirements of block division,and the mixed block mode effectively improve the effect of compressed sensing.Through simulation experiments,it can be verified that the method proposed in this paper effec-tively improves the quality of image reconstruction,especially the mixed block method,which significantly improves the speed and quality of image reconstruction.
Based on N×N-type sampling law of subharmonic method,incremental sampling is introduced,and an incremental N×N-type sampling law of subharmonic method is proposed for numerical simulation of ocean turbulence phase screen.This method uses the refractive index fluctuation spectrum proposed by Nikishov to simulate the phase of ocean turbulence,and verifies the accuracy of the phase screen generated by the phase structure function and compen-sation effect.By changing the number of incremental regions,sampling levels and subharmonic orders,the influence of phase screen parameters on the accuracy of phase screen is compared and analyzed.In addition,the proposed meth-od is compared with the subharmonic method of N×N-type sampling law,the modified subharmonic method and the improved subharmonic method.The results show that when the subharmonic order of the incremental N×N-type sam-pling law of subharmonic method is 11,the compensation effect can reach 0.999 5,and the simulation speed is faster with the same accuracy.
In order to improve the effect of target detection,a 3D LiDAR active imaging target detection method based on deep learning algorithm is designed.By using the generative adversarial network of deep learning algorithm,the clutter interference in the active imaging process of 3D LiDAR is eliminated,and the three-dimensional target im-age without clutter interference is obtained.The loss function of the generative model and the countermeasure model is designed.The point cloud coding layer of the end-to-end deep neural network is used to extract the 3D image features of the target without clutter interference and input them into the target detection layer.The target detection candidate frame is output through the target detection layer,and the final target detection frame is determined by the combination of non-maximum value and mixed confidence,and the 3D LiDAR active imaging target detection is completed.The experimental results show that the proposed method can effectively eliminate clutter interference and obtain three-di-mensional target images without clutter interference.The proposed method can effectively complete the target detection in 3D LiDAR active imaging,and the intersection ratio of the proposed method is higher than the threshold value for different target motion blur length pixels,indicating that the proposed method has high target detection accuracy.
