Pulse duration

About: Pulse duration is a research topic. Over the lifetime, 19429 publications have been published within this topic receiving 286507 citations.

1 kW 1 mJ eight-channel ultrafast fiber laser.

Abstract: An ultrafast fiber chirped-pulse amplifier comprising eight coherently combined amplifier channels is presented. The laser delivers 1 kW average power at 1 mJ pulse energy and 260 fs pulse duration. Excellent beam quality and low-noise performance are confirmed. The laser has proven suitable for demanding scientific applications. Further power scaling is possible right away using even more amplifier channels.

Ultrafast carrier diffusion in gallium arsenide probed with picosecond acoustic pulses

Abstract: We describe an experimental investigation of the generation and detection of picosecond acoustic-phonon pulses in a thin slab of GaAs using ultrashort optical pulses. Comparison of the optical phase variation with a simple theory for ambipolar diffusion indicates that carrier diffusion has a significant effect on the shape of the phonon pulses generated. The phonon pulse duration is measured to be \ensuremath{\sim}25 ps, four times longer than that expected from optical-absorption considerations alone, indicating that hot carriers penetrate more than 100 nm into the sample during the phonon pulse generation process.

Effects of CO2 laser pulse duration in ablation and residual thermal damage: implications for skin resurfacing.

Abstract: Background and Objectives Resurfacing with the CO2 laser is rapidly gaining acceptance for skin rejuvenation. Advances in CO2 laser and scanning technology allow for precise tissue removal with minimal thermal damage. High energy CO2 laser pulses have been widely used effectively to smooth the surface of facial skin; however, pulse duration effects on ablation and thermal damage have not been systematically studied over the millisecond region (0.25–10 ms). Study Design/Materials and Methods This study characterizes the ablation threshold, heat of ablation, and residual thermal damage in skin resulting from CO2 laser pulses with a Gaussian beam profile. Mass loss from fresh pig skin was measured with an analytical balance, and residual thermal damage was determined through histology. Results Pulse durations >1 ms were associated with higher ablation thresholds and localized increased thermal damage. Conclusions Our results show that although pulse duration is an important determinant in ablation and thermal damage, irradiance is more critical as an independent parameter in predicting the effects of CO2 laser pulses. © 1996 Wiley-Liss, Inc.

Generation of supershort avalanche electron beams and formation of diffuse discharges in different gases at high pressure

Abstract: This paper presents the results of experimental investigations on the generation of supershort avalanche electron beams (SAEB) at nanosecond discharges initiated in gas-filled diodes. In air, at a pressure of 1 atm with a sharply non-uniform electric field, an SAEB is generated from the inter-electrode gap at a solid angle exceeding 2π sr. Reduction of gap d between the cathode and the anode leads to a decrease in the current amplitude of the beam incident on the lateral walls of the gas-filled diode and in an increase in the pulse duration of the beam current both in the axial and radial directions. Pulses of the beam current initiated on the lateral surface of a tube cathode have been recorded. It is shown that to generate electrons with an ‘anomalous’ energy, cathodes with an increased radius of curvature should be used.

Direct Intense Pulsed Light Sintering of Inkjet-Printed Copper Oxide Layers within Six Milliseconds

Abstract: We demonstrate intense pulsed light (IPL) sintering of inkjet-printed CuO layers on a primer-coated porous PET substrate to convert the electrically insulating CuO into conductive Cu. With this approach, conductive layers are obtained in less than 1 s after the printing process. The IPL sintering was performed for high productivity with minimum duration and repetition of IPL irradiation to evaluate the effect of pulse number and energy output on the conductivity and morphology of the sintered Cu layers. Depending on the energy output, sheet resistances were measured as 0.355, 0.131, and 0.121 Ω·□–1 by exposure energy of 5.48 (single pulse), 7.03 (double pulse), and 7.48 J·cm–2 (triple pulse), respectively. In contrast, an excessive energy with relatively short pulse duration causes a delamination of the Cu layer. The lowest resistivity of about 55.4 nΩ·m (corresponds to about 30% conductivity of bulk Cu) was obtained by an IPL sintering process of 0.26 s after the printing, which was composed of 2 ms trip...