Research Of Initiactive Waveform Shaping Technology On The Hundred-joule Solid Laser System

Initiative waveform shaping can help improve the output laser’s performanceand enhance the efficiency of THG.The ideal waveform can be calculated byderiving Laser rate equations and transport equations. But for nonlinear partialdifferential equations, its analytical solution is difficult to obtain. While solving thenumerical solution, large errors may be introduced. Based on the needs of actuallaser applications, a feedback method based on the output waveform is raised. Andthis waveform compensation scheme is verified by experiment. A square wave pulsecan be obtained.In this paper, focusing on the establishing of this feedback waveform shapingprogram,its content is divided into three parts:(1)the foundation of on-linemeasurement and synchronization system;(2) analysisof waveform distortion andgain amplification;(3) the design and actualverification of waveform shapingprogram. In base systemThe establishment of on-line measurement and synchronization system comesto the first, because it is necessary for feedback calculation. In base system, a swashplate is used to sampling the reflecting light, while in third harmonic systemtransmission light is used for sampling. Sampling rate’s calibration will be carriedon to ensure it is accurately. The main laseris lessened1:10and transported tosurface of the CCD. Some of the sampling light is focused and attenuated intophototube.And then based on Frantz-Nodvik equation, the amplificationprocessisanalyzed. When a large signal is injected into the gain medium,Since theleading edgefirstly inject into the amplifying medium, a high gain will be got. Theupper state particlesconsumes more, while the trailing edge gets less gain. This isthe main reason of the laser pulse waveform distortion.At last a wave pulse like e exponential functionwill be written into the AWG infront end. The output waveform will be entered into the compensation program asthe basis.5ns and3ns square wave are carried out actually. The desired square wavecan be got after one or two issued times.This solution can save run times sent of thisdevice as well as improve work efficiency.