Research On High Power Infrared Chaotic Laser For Lidar

Chaotic signal has the characteristics of noise-like,high bandwidth,strong randomness,etc,and has important application value in the fields of encrypted communication,random number generator and vehicle lidar.Especially in the field of lidar,the power of chaotic laser determines the effective detection range of the radar.Therefore,the realization of high-power chaotic laser generation is an inevitable trend in the development of vehicle chaotic lidar.The 1550nm is in the near-infrared band of the laser.Compared with the 800?1000nm band laser signal used by traditional lidars,the 1550nm laser has a stronger penetrating ability under low-visibility weather such as haze,sand and dust,and is safer to the human eye.Therefore,studying the near-infrared chaotic lidar based on 1550nm laser is of great significance for improving the detection performance of vehicle lidar in severe weather.In this paper,the generation of 1550nm chaotic laser with close to W-level power was realized,and it was applied to lidar ranging.The main work and results of this paper are as follows:1.The generation principle,characteristics and development status of chaotic laser was introduced.The advantages of high-power 1550nm chaotic laser in lidar ranging were analyzed,and the research status of high-power semiconductor lasers was briefly introduced.2.The working principle and internal structure of semiconductor laser was introduced.The generation of chaotic laser was theoretically simulated.And the effects of laser parameters,especially external parameters(such as injection current,feedback intensity,etc.)on the performance of chaotic laser spectra,spectral widths,and autocorrelation characteristics.Influences were analyzed.3.First,the free-running characteristics of high-power multi-mode F-P semiconductor lasers were experimentally studied.Subsequently,the operating characteristics of the F-P semiconductor laser based on the optical feedback structure were further studied.By changing the feedback intensity and the injection current,the path of the laser entering the chaotic state was analyzed.We found that through experiments:when the injection current was 1.5I_th(threshold current),the laser entered a chaotic state from the periodic state,and when the injection current increased to 3I_th,the laser would generate a chaotic signal under low feedback intensity.The comparison concluded that the increase in the injection current will cause the laser enters the chaotic state faster.At the same time,it was found that when the injection current is changed under the same feedback intensity,the bandwidth of the signal will increase first and then decrease as the current increases.4.The ranging performance of chaotic lidar was studied.The time domain characteristics and autocorrelation characteristics of chaotic laser signals under different injection currents and feedback intensities were analyzed.And the optimal injection current and feedback intensity parameter ranges are obtained.The experimental results of chaotic lidar ranging showed that the 1550nm high-power chaotic lidar could achieve 6.3cm spatial resolution independent of distance.