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Talence, France

Mottay E.,Amplitude Systemes | Hoenninger C.,Amplitude Systemes | Kling R.,ALPhANOV | Choi J.,Korea Institute of Machinery and Materials | Cho S.-H.,Korea Institute of Machinery and Materials
2015 11th Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2015 | Year: 2016

The development of new display technologies, such as organic LEDs and flexible displays, require significant advances in laser sources and manufacturing processes. We report on new laser technologies and optimized processes. © 2015 IEEE.

Jolly A.,ALPhANOV | Jolly A.,Cea Center Detudes Scientifiques Et Techniques Daquitaine | Chassagne B.,ALPhANOV | Jolly J.-C.,University of Notre Dame
Optics Communications | Year: 2013

An original design of generic interest is proposed for fast imaging, in the field of sub-terahertz frequencies, by means of resonant coupling between an ultra-thin photo-thermal converter and a metallic grid upstream an infrared camera. The material is a sheet of polyimide material with a high content of absorptive carbon inclusions. We make use of the large difference between the IR and THz wavelengths in a quarter-wave planar geometry, to ensure a highly efficient and stable conversion process. A complete setup has been implemented for demonstration purposes, using the beam from a Gunn diode at 110 GHz. Experimental results are in good agreement with the predictions from the numerical model, which helps to validate the concept and the requirements for geometrical adjustment. © 2013 Published by Elsevier B.V.

Torres R.,ALPhANOV | Kaempfe T.,Jean Monnet University | Delaigue M.,Amplitude Systemes | Parriaux O.,Jean Monnet University | And 5 more authors.
Journal of Laser Micro Nanoengineering | Year: 2013

Ultrashort pulse lasers have been established as precise and universal tools for the micro-machining of solid materials (cutting, texturing ...). For these applications the quality of the cutting cross-section is important. The use of a Gaussian beam profile and linear polarization leads to tapered cutting sidewalls. It is possible to change the polarization orientation in order to machine a material for obtaining straight and vertical sidewalls. For this purpose a specific polarization converter was used. The transformation of the polarization distribution from linear to radial and azimuthal is done by a subwavelength, binary grating creating a π phase shift between the TE and TM transmitted waves. In this paper we report on investigations on the influence of laser polarization (radial, azimuthal, circular, linear) on the ablation characteristics of molybdenum and PZT using an Yb doped crystal laser (500 fs) and compare these results with previously published results.

Lopez J.,French National Center for Scientific Research | Torres R.,ALPhANOV | Zaouter Y.,Amplitude Systemes | Georges P.,Institute Optique Graduate School | And 3 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

Ultrafast laser are well known to provide cold ablation on metals at near-threshold fluence and low repetition rate. However increasing the repetition rate from multi-kHz to MHz may produce a heat accumulation in the target depending on both the scanning speed and the material properties. This potentially leads to two effects: enhanced ablation efficiency as well as increased heat affected zone. To identify potentials and limitations while maintaining highest processing quality is the main objective of this paper and a key issue for many industrial applications. We present some comprehensive results on the influence of both repetition rate and pulse duration on the ablation efficiency. This investigation is performed using a new generation of high power Ytterbium doped fiber ultrafast laser with a tunable pulse duration ranging from 350fs to 10ps and with repetition rate going from 250kHz to 2MHz. The output power is up to 40 watt. The effect of both parameters above on ablation efficiency of Al, Cu and Mo is discussed with respect to removal rate measurement and SEM analysis. © 2013 Copyright SPIE.

Lopez J.,ALPhANOV | Lopez J.,University of Bordeaux 1 | Kling R.,ALPhANOV | Torres R.,ALPhANOV | And 5 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

In order to minimize thermal load to the workpiece pico- and femtosecond lasers gain an increasing market share in industrial applications such as surface structuring or thin film selective ablation. Due to nonlinear absorption they are capable to process any type of material (dielectrics, semiconductors, metals) and provide an outstanding quality suppressing heat affects on the workpiece. In this paper, 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, which could be used in the picosecond regime as well as in the femtosecond regime by simply changing the seed laser source. In the picosecond regime the oscillator pulses, ranging from 10 to 34ps, can be directly amplified which leads to a quite simple and efficient amplifier architecture. On the other hand, a broadband femtosecond oscillator and a CPA configuration can be used in order to obtain pulse duration down to 900fs. We compare these results to recently obtained achievements using commercial femtosecond lasers based on Yb-doped crystals and fibers and operating at comparable output power levels, up to 15Watt. Finally, we have considered etch rate and process efficiency for both ps- and fs-regimes as a function of average power, of fluence and of intensity. © 2012 SPIE.

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