scholarly journals Micromachining of Invar with 784 Beams Using 1.3 ps Laser Source at 515 nm

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2962 ◽  
Author(s):  
Petr Hauschwitz ◽  
Bohumil Stoklasa ◽  
Jiří Kuchařík ◽  
Hana Turčičová ◽  
Michael Písařík ◽  
...  
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Light Emitting Diode ◽  
Laser System ◽  
Ultrashort Pulses ◽  
High Energy ◽  
Laser Source ◽  
Organic Light Emitting Diode ◽  
Energy Pulse ◽  
Cost Efficient ◽  
Monitoring Module

To fulfil the requirements for high-resolution organic light-emitting diode (OLED) displays, precise and high-quality micrometer-scale patterns have to be fabricated inside metal shadow masks. Invar has been selected for this application due to its unique properties, especially a low coefficient of thermal expansion. In this study, a novel cost-efficient method of multi-beam micromachining of invar will be introduced. The combination of a Meopta beam splitting, focusing and monitoring module with a galvanometer scanner and HiLASE high-energy pulse laser system emitting ultrashort pulses at 515 nm allows drilling and cutting of invar foil with 784 beams at once with high precision and almost no thermal effects and heat-affected zone, thus significantly improving the throughput and efficiency.

Carbon nanotube accelerator — Path toward TeV/m acceleration: Theory, experiment, and challenges

2019 ◽  
Vol 34 (34) ◽  
pp. 1943005 ◽  
Author(s):  
Young-Min Shin
Keyword(s):  
Particle Physics ◽  
Laser System ◽  
Large Degree ◽  
High Energy ◽  
Analytic Description ◽  
High Energy Particle ◽  
High Gradients ◽  
Cost Efficient ◽  
Energy Gains ◽  
Conceptual Foundations

Aspirations of modern high energy particle physics call for compact and cost efficient lepton and hadron colliders with energy reach and luminosity significantly beyond the modern HEP facilities. Strong interplanar fields in crystals of the order of 10–100 V/Å can effectively guide and collimate high energy particles. Besides continuous focusing crystals plasma, if properly excited, can be used for particle acceleration with exceptionally high gradients [Formula: see text](TeV/m). However, the angstrom-scale size of channels in crystals might be too small to accept and accelerate significant number of particles. Carbon-based nano-structures such as carbon-nanotubes (CNTs) and graphenes have a large degree of dimensional flexibility and thermo-mechanical strength and thus could be more suitable for channeling acceleration of high intensity beams. Nano-channels of the synthetic crystals can accept a few orders of magnitude larger phase-space volume of channeled particles with much higher thermal tolerance than natural crystals. This paper presents conceptual foundations of the CNT acceleration, including underlying theory, practical outline and technical challenges of the proof-of-principle experiment. Also, an analytic description of the plasmon-assisted laser acceleration is detailed with practical acceleration parameters, in particular with specifications of a typical tabletop femtosecond laser system. The maximally achievable acceleration gradients and energy gains within dephasing lengths and CNT lengths are discussed with respect to laser-incident angles and the CNT-filling ratios.

scholarly journals Conceptual Design of a Laser Driver for a Plasma Accelerator User Facility

Instruments ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 40 ◽  
Author(s):  
Guido Toci ◽  
Zeudi Mazzotta ◽  
Luca Labate ◽  
François Mathieu ◽  
Matteo Vannini ◽  
...  
Keyword(s):  
Conceptual Design ◽  
Repetition Rate ◽  
Beam Quality ◽  
Laser System ◽  
Average Power ◽  
Ultrashort Pulses ◽  
High Energy ◽  
Plasma Accelerator ◽  
User Facility ◽  
Very High

The purpose of the European project EuPRAXIA is to realize a novel plasma accelerator user facility. The laser driven approach sets requirements for a very high performance level for the laser system: pulse peak power in the petawatt range, pulse repetition rate of several tens of Hz, very high beam quality and overall stability of the system parameters, along with 24/7 operation availability for experiments. Only a few years ago these performances were considered unrealistic, but recent advances in laser technologies, in particular in the chirped pulse amplification (CPA) of ultrashort pulses and in high energy, high repetition rate pump lasers have changed this scenario. This paper discusses the conceptual design and the overall architecture of a laser system operating as the driver of a plasma acceleration facility for different applications. The laser consists of a multi-stage amplification chain based CPA Ti:Sapphire, using frequency doubled, diode laser pumped Nd or Yb solid state lasers as pump sources. Specific aspects related to the cooling strategy of the main amplifiers, the operation of pulse compressors at high average power, and the beam pointing diagnostics are addressed in detail.

scholarly journals Advances in Imaging Diagnostics for Spray and Particle Research in High-Speed Flows

2020 ◽  
Vol 10 (4) ◽  
pp. 1450
Author(s):  
Julien Manin ◽  
William D. Bachalo
Keyword(s):  
High Speed ◽  
Imaging System ◽  
Light Emitting Diode ◽  
Laser System ◽  
Optical Design ◽  
High Energy ◽  
Solid Particles ◽  
Diagnostic Methods ◽  
Microscope Imaging ◽  
High Speed Flows

Measurements of high-pressure sprays and particle fields in high-speed flows have been very challenging for the existing instrumentation. Deformed drops or solid particles significantly limit the range of experimental methods that can be applied for detailed, quantitative measurements. We developed advanced microscope imaging equipment and diagnostic methods to characterize fast-moving droplets or particles. We designed illumination systems based on high-power light-emitting diode (LED) and incoherent laser devices capable of short, intense light pulses. We compared their characteristics and performance separately, as well as their interaction within a complete line-of-sight microscope imaging system. The optical design of the microscope setup was optimized via ray tracing simulations showing high energy losses for LED illumination compared to laser radiation, as confirmed experimentally. The energy transmission measurements provided guidance about the pulse energy density necessary to maximize camera response and signal-to-noise ratio. Characterization testing supported that both illumination systems are valid options for microscopy applications, with an advantage to LED for image quality and resolution performance, but a strong limitation to distance, where the multi-beam laser system demonstrated its superiority.

Efficient, Color Stable White Organic Light-Emitting Diode Based on High Energy Level Yellowish-Green Dopants

2008 ◽  
Vol 20 (10) ◽  
pp. 1957-1961 ◽  
Author(s):  
Young-Seo Park ◽  
Jae-Wook Kang ◽  
Dong Min Kang ◽  
Jong-Won Park ◽  
Yoon-Hi Kim ◽  
...  
Keyword(s):  
Energy Level ◽  
Light Emitting Diode ◽  
High Energy ◽  
Light Emitting ◽  
High Energy Level ◽  
Organic Light Emitting Diode ◽  
Yellowish Green ◽  
Organic Light

High-energy pulse-burst laser system for megahertz-rate flow visualization

2000 ◽  
Vol 25 (22) ◽  
pp. 1639 ◽  
Author(s):  
Pingfan P. Wu ◽  
Richard B. Miles
Keyword(s):  
Flow Visualization ◽  
Laser System ◽  
High Energy ◽  
Pulse Burst ◽  
Energy Pulse

scholarly journals Characterization of Absorption Losses and Transient Thermo-Optic Effects in a High-Power Laser System

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 94
Author(s):  
Lukasz Gorajek ◽  
Przemyslaw Gontar ◽  
Jan Jabczynski ◽  
Jozef Firak ◽  
Marek Stefaniak ◽  
...  
Keyword(s):  
High Power ◽  
Continuous Wave ◽  
Beam Quality ◽  
Laser System ◽  
Infrared Camera ◽  
High Energy ◽  
Laser Source ◽  
Transient Temperature ◽  
Temperature Profiles ◽  
Beam Diameter

(1) Background: The modeling, characterization, and mitigation of transient lasers, thermal stress, and thermo-optic effects (TOEs) occurring inside high energy lasers have become hot research topics in laser physics over the past few decades. The physical sources of TOEs are the un-avoidable residual absorption and scattering in the volume and on the surface of passive and active laser elements. Therefore, it is necessary to characterize and mitigate these effects in real laser systems under high-power operations. (2) Methods: The laboratory setup comprised a 10-kW continuous wave laser source with a changeable beam diameter, and dynamic registration of the transient temperature profiles was applied using an infrared camera. Modeling using COMSOL Multiphysics enabled matching of the surface and volume absorption coefficients to the experimental data of the temperature profiles. The beam quality was estimated from the known optical path differences (OPDs) occurring within the examined sample. (3) Results: The absorption loss coefficients of dielectric coatings were determined for the evaluation of several coating technologies. Additionally, OPDs for typical transmissive and reflective elements were determined. (4) Conclusions: The idea of dynamic self-compensation of transient TOEs using a tailored design of the considered transmissive and reflecting elements is proposed.

scholarly journals Large-Beam Picosecond Interference Patterning of Metallic Substrates

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4676
Author(s):  
Petr Hauschwitz ◽  
Dominika Jochcová ◽  
Radhakrishnan Jagdheesh ◽  
Martin Cimrman ◽  
Jan Brajer ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Laser System ◽  
Hierarchical Structures ◽  
High Energy ◽  
Contact Angles ◽  
Surface Structures ◽  
Laser Source ◽  
Metallic Substrates ◽  
And Tungsten

In this paper, we introduce a method to efficiently use a high-energy pulsed 1.7 ps HiLASE Perla laser system for two beam interference patterning. The newly developed method of large-beam interference patterning permits the production of micro and sub-micron sized features on a treated surface with increased processing throughputs by enlarging the interference area. The limits for beam enlarging are explained and calculated for the used laser source. The formation of a variety of surface micro and nanostructures and their combinations are reported on stainless steel, invar, and tungsten with the maximum fabrication speed of 206 cm2/min. The wettability of selected hierarchical structures combining interference patterns with 2.6 µm periodicity and the nanoscale surface structures on top were analyzed showing superhydrophobic behavior with contact angles of 164°, 156°, and 150° in the case of stainless steel, invar, and tungsten, respectively.

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