Theoretical Study Of Pulsed Erbium-doped Fiber Laser Based On Laser Ranging

In car-assisted driving,the vehicle's active anti-collision system has always been a high-end device that high-end commercial vehicles can only equip.With the development of pulsed fiber laser technology,fiber-laser-based ranging technology has received extensive attention.Fiber lasers have many advantages,such as good beam quality,high fiber gain,high efficiency,low threshold,tunable,compact structure,reliable operation,and good heat dissipation.Based on this,this paper mainly studies the theory of pulsed fiber laser based on laser ranging system and the related distance measurement research.First,this paper studies the basic theory of fiber lasers,such as the basic theory of saturable absorber-based pulse technology and laser ranging technology.On the basis of theoretical research,the output characteristics of Ytterbium-doped fiber lasers were studied in a specific simulation environment through software simulation experiments.The principle of the Ytterbium-doped fiber laser and the derivation of the rate equation are studied.The distribution of the pump signal light in the cavity is simulated.Through numerical simulation,the relationship between signal distribution and pump light distribution within the fiber is obtained in a specific simulation environment.At an input power of 20 W,the output power is 16 W.Secondly,the output characteristics of passively Q-switched Ytterbium-doped fiber lasers are studied.The basic structure of the erbium-doped pulsed fiber laser resonator model,rate equation,and Ytterbium-doped pulsed fiber laser is theoretically studied,and the traveling wave describing the resonant cavity is used.The model deduces the mathematical model of the theoretical model and output characteristics of the pulsed fiber laser and the number of photons in the cavity.By solving the linear partial differential equations with initial boundary conditions,the numerical simulation of the output characteristics of pulsed fiber lasers is studied.In a specific simulation environment,the length of the gain fiber and the influence of the length of the saturable absorber on the peak power of the output pulse are studied.The peak power is maximized through parameter optimization.At the pump power of 5W,the output pulse width is 0.8?s,the pulse peak power is 26 W,the average power is 2W,and the pulse energy is 20?J.Based on the above pulse energy,atmospheric transmittance of 1,and object reflectivity of 0.1,the minimum detection power is calculated to be 3.9x10-7W,which can reach 200 meters under the condition of selecting an appropriate APD(avalanche diode).Finally,according to the distance measurement application scenario of this paper,the maximum measurement distance of the laser is calculated,and the maximum pulse detection distance calculated by the simulation pulse output parameter is used to obtain the minimum detection power,so as to select a reasonable fiber detector.By using the distance measurement principle of fiber laser,a laser ranging system can be designed for distance measurement,and the ranging process of each module in laser ranging is studied.Based on the designed dual rangefinder ranging scheme,a preliminary ranging experiment based on RPLIDAR-A1 rangefinder was built to verify the rationality of the ranging scheme.In the experiment based on RPLIDAR,under certain conditions,the maximum error of using a single range finder can be found to be 0.9%,while when using a dual range finder,the error accuracy is reduced to 0.3%,and the error rate is reduced by 66%.And it can be applied to laser ranging systems.