Papers by Keyword: Picosecond

Abstract: Aiming to discharge feebly, improving the frequency of MEDM power pulse is an ideal choice. But due to the influence of power resistor, capacitor, inductor with stray capacitance and stray inductance, increasing the higher pulse power frequency met bottleneck. Through the analysis of MEDM discharging circuit and routes, this paper puts forward the theory of not using components, but depending on the natural oscillation of MEDM machine tools and connection line to make MEDM pulse power. Through theoretical calculation and simulation, the oscillation period of discharging circuit can be controlled in 1.5ns, and the pulse width can be less than 750 Ps. It provides theoretical support for making picosecond pulse power and nanometer manufacturing with MEDM.

Abstract: Pico and femtosecond lasers present a growing interest for industrials applications such as surface structuring [1] or thin film selective ablation [2]. Indeed, they combine the unique capacity to process any type of material (dielectrics, semiconductors, metals) with an outstanding precision and a reduced affected zone. We report on results about surface engraving of metals (Al, Cu, Mo, Ni), semiconductor (Si) and polymer (PC) using a picosecond thin disk Yb:YAG-amplifier. The pulse duration of this source can be changed using two different configurations: direct amplification of a 34ps-oscillator on one hand, and 1ps-chirped pulse amplification (CPA) scheme on the other hand. The results obtained with this thin disk laser are compared to ones achieved with two commercial femtosecond lasers respectively based on Yb-doped crystals and fibers, and operating at similar output power levels (up to 15Watt).