Synchronization Of Broadband Chaotic Laser Based On VCSEL And Its Theoretical Studies

Along with the electronic era, big data gets more and more convenient,Internet plus transfer rate of the information age is more and more quickly,the whole society of information capacity, communication speed,communication security has been more and more attention, therefore has the security system of large capacity and high communication rate, safety factor high also has more application prospects and market. Chaotic signal has high complexity and unpredictability of the characteristics can be used to transmit high-speed security as the chaotic carrier of information. Due to the chaotic communication baindwidth of the electronic circuit, and its dimension is low, unable to adapt to long-distance transmission, and optical communication using semiconductor laser with optical fiber coupling to achieve long-distance transmission, and the encryption key is a combination of physical parameters and application parameters, can not be changed with the dual advantages and controllability. Vertical cavity surface emitting lasers (VCSEL) is a new type of micro cavity laser, has the advantages of optical circular, optical fiber coupling efficiency and high integration and easy two-dimensional array, it will replace the SL application in ordinary communication system, can improve the performance of the system.Based on the research and development of optical chaos chaos VCSEL encryption from learning, comprehensive consideration to meet the needs of high-speed information transmission, rate equations of light vertical cavity surface emitting lasers into the dual feedback under the chaotic synchronization system and its corresponding. Through the MATLAB numerical calculation of the corresponding model, a detailed analysis of the multiple vertical cavity semiconductor lasers with optical injection strength, harmonic parameters between laser and mismatch between time and frequency conditions of laser optical feedback strength,optical feedback, respectively on the chaotic sequence diagram, phase diagram, Poincare map, frequency spectrum the correlation coefficient and many aspects are analyzed, the influence on the chaotic synchronization and chaotic laser output bandwidth, suitable range of increasing injection strength, can increase the output bandwidth of chaotic laser and laser synchronization between the coefficient increased. Considering the response of synchronous VCSEL and bandwidth, because the correlation coefficient between the laser response of more than 95% in order to demodulation, strength and mismatch coefficient by adjusting appropriate optical injection, can finally get 30GHz of the complete synchronization of chaotic laser output. In addition to increasing the frequency detuning of chaotic laser can increase the bandwidth, but will weaken the system between the corresponding synchronization effect; considering the problem of parameter mismatch between the common system, the simulation results show that although it will reduce the synchronization effect of the system, but the proper range still can be used in synchronous communication. So, considering the broadband carrier synchronous communication based on the system by selecting the appropriate parameters to achieve the wideband synchronization of chaotic laser output.Because the same laser does not exist in reality, through the research on the laser parameter mismatch of bandwidth and synchronization performance,determine the range of parameters can meet the synchronization effect,further guidance to the actual laser choice.