Active two-pulse superposition technique of a pulsed Nd:YAG laser

Abstract

In manufacturing processes, various and suitable pulse shapes are required for the purpose of materials processing, and the pulse shape is regarded as a dominant factor according to the specific property of materials. Therefore, this study has undertaken to generate the correct ones by using the two-pulse superposition technique. The pulsed Nd:YAG laser using a multi-mesh inductor L and capacitor C network and the pulse superposition technique is described. We have tried to superpose two pulses with the single shot multivibrator (SSM: 74LS123) having two silicon-controlled rectifiers (SCRs) which control the delay time of the two gate turn-on signals. One is a main rectangular pulse, and the other is a superposed sinusoidal pulse. The use of this technique might impart a number of advantages to people who need a suitable pulse shape for particular applications such as welding, cutting, and drilling. In addition, we compared the case of no superposition and applied input energy of 100 J in only the main circuit with that of superposition and applied input energy of 75 J in the main circuit and 25 J in the superposing circuit. It is found that the maximum efficiency of 4.5% is obtained within the range of delay time less than 230 s by adjusting the delay time from 0 to 1 ms. © 1998 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(98) Subject terms: materials processing; pulsed Nd:YAG laser; multi-mesh inductor L and capacitor C; pulse superposition technique; suitable pulse shape.

Modeling and simulation of pulsed Nd:YAG laser system

“…To obtain high pumping efficiency it is better to use a flashlamp that matches the laser rod dimensions so the required flash lamp parameters are determined using the simulation model and found to be with an arc length of 11 cm and bore diameter of 8 mm [4,5,18]. Design and analysis of pulsed light sources was described by a lot of authors [2][3][4][5][6]. High voltage circuits simulators are not available, so the flashlamp power supply was modeled and simulated using MATLAB SIMULINK.…”

“…Nd:YAG media is the most commonly used media of solid-state lasers in many fields. Its popularity has come from its wide range of output powers and the versatile output shapes available from a cw and a pulsed modes [2,3]. Many research efforts directed to study the performance of cw-pumped systems have been reported in details in [4,5].…”

“…The design of a flashlamp power supply for pumping solid-state lasers was presented in [12,13]. Compactness, losses reduction efficiency enhancement of the pump source power supply and the pump source pulse shape were studied in many researches such as in [2,3,14,15]. Again each subsystem was individually studied.…”