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Ultra-short laser pulses are particularly suitable for processing micro tools made of ultra-hard and dielectric materials. Ultra-short laser pulses provide a contact-free and precise fabrication of heat-sensitive materials such as visible spectra range. Visible spectra range has unique properties, which makes it an essential material in the tool, jewelry, and semiconductor industries. The processing of visible spectra range by ultra-short laser pulses is complex, as visible and near-infrared light is generally not absorbed. However, the intensity of ultra-short laser pulses is extremely high, so that the absorption scales nonlinearly with the intensity and, thus, visible or near-infrared light can be absorbed. The complexity also results from many partially interdependent process variables, such as the repetition rate, pulse overlap, track overlap, and scan speed. Excellent knowledge of the process is, therefore, essential for the production of micro tools. To make the laser processing accessible to a broader user field, the operator can be supported by a computer-aided design (CAD). The aim of this research was to the modeling of an ultra-short high-intensity laser for the visible spectra range in different environments of the angle of incidence, scanning speed, pulse, and track overlap. The experimental process included ultra-short pulsed laser processing of visible spectra range and surface analysis concerning modifications and ablation of the ultra-short laser. Ablation volumes were analyzed for single pulses, multi-pulses, and pockets. Pump-probe experiments reveal transient optical properties such as transmission or reflectivity. It was concluded that ultraviolet laser pulses are best suited to induce damage or modifications to visible spectra range surfaces. Additionally, shorter wavelengths have further advantages such as potentially longer Rayleigh lengths and smaller spot sizes.

High intensity lasers are of substantial value in quantum memory research. We put together a double-pass tapered amplifier based laser light source for hot atomic vapor quantum memory experiments.

The recent development of ultra-high intensity laser facilities is finally opening up the possibility of studying high-field quantum electrodynamics in the laboratory. Arguably, one of the central phenomena in this area is that of quantum radiation reaction experienced by an ultra-relativistic electron beam as it propagates through the tight focus of a laser beam. In this paper, we discuss the major experimental challenges that are to be faced in order to extract meaningful and quantitative information from this class of experiments using existing and near-term laser facilities.

The use of plasmas provides a way to overcome the low damage threshold of classical solid-state based optical materials, which is the main limitation encountered in producing and manipulating intense and energetic laser pulses. Plasmas can directly amplify or alter the characteristics of ultra-short laser pulses via the three-wave coupling equations for parametric processes. The strong-coupling regime of Brillouin scattering (sc-SBS) is of particular interest: recent progress in this domain is presented here. This includes the role of the global phase in the spatio-temporal evolution of the three-wave coupled equations for backscattering that allows a description of the coupling dynamics and the various stages of amplification from the initial growth to the so-called self-similar regime. The understanding of the phase evolution allows control of the directionality of the energy transfer via the phase relation between the pulses. A scheme that exploits this coupling in order to use the plasma as a wave plate is also suggested.

Laser particle acceleration is now in a new trend due to an enormous worldwide effort to increase the peak power of femtosecond lasers, as well as increasing their average power in order to make them useful for applications. The leading example is the Extreme Light Infrastructure in Europe, which has led to the establishment of three large research facilities in the Czech Republic, Romania and Hungary that host some of the most powerful lasers worldwide (above PW peak power). This action is now being followed by the USA LaserNetUS initiative, that comprises all the big laser facilities in US, and similar efforts also happen in Asia. We are starting a program to establish a laser accelerator facility in Brazil, aiming to produce radiation (electrons, protons and X rays) to be used in medical applications, like X ray and electron therapy, nuclear reactions and, eventually, protontherapy.

High-field THz pulse generation by the interaction of high intensity femtosecond laser with aligned nanorods target have been investigated experimentally and theoretically which shows 13.8 times enhancement in THz pulse energy in ≤ 20 THz.

The objective of the Apollon 10 PW project is the generation of 10 PW peak power pulses of 15 fs at $1~\text{shot}~\text{min}^{-1}$ . In this paper a brief update on the current status of the Apollon project is presented, followed by a more detailed presentation of our experimental and theoretical investigations of the temporal characteristics of the laser. More specifically the design considerations as well as the technological and physical limitations to achieve the intended pulse duration and contrast are discussed.

Herpes simplex virus (HSV) is one of the most common viral infections of the human being. Although most of the seropositive persons do not manifest symptoms, infected individuals may present recurrent infections, characterized by cold sores. HSV-1 infection can result in potentially harmful complications in some patients, especially in those with compromised immunity. We report a clinical case of a patient with severe oral HSV-1 infection in the lower lip. The treatment of the lesions with the association of high-intensity (erbium-doped yttrium aluminum garnet, 2.94 mum, 80 mJ/pulse, 2-4 Hz) and low-intensity (indium gallium aluminum phosphide, 660 nm, 3.8 J/cm(2), 10 mW) lasers has not been reported in the literature. During treatment, no systemic or topical medication was used. Pain sensitivity was completely gone after the first irradiation with the low-intensity laser. During the healing process, lesions were traumatized twice, on the days 4 and 7. Even though the lesions were completely healed within 10 days.

The early and reliable detection of breast cancer is often difficult with conventional mammography, especially within dense breast parenchyma. An alternative approach using x-rays are phase-sensitive imaging techniques, which are able to visualize the borders of tissues with different refraction indices with very high contrast. These phase contrast imaging techniques can generate projection images with much less glandular dose than conventional mammography. Even the acquisition of phase contrast CT data sets with an acceptable exposure dose is possible. As brilliant x-ray beams are required for phase contrast imaging, which up to now were only available at synchrotron facilities, these methods were restricted to only a few laboratories. However, with the advent of newly developed high intensity lasers which are also able to produce such radiation, a widespread and affordable use of this technique seems realistic. The further development of phase contrast imaging is funded by the excellence cluster MAP of the Munich universities.

This report is the final report for the 2008-2014 cycle of DOE support for the Committee on Atomic, Molecular, and Optical Sciences. Highlights of the committee’s activities over this period included: • Meetings of the committee were held semiannually (Washington, DC in April and Irvine, CA in October) for four of the six years and annually the last two years (Washington, DC in April). • Committee meetings included half-day focus sessions on each of the areas identified in the last AMO decadal survey as having great scientific promise and short summaries of the focus session were prepared and delivered to sponsoring agencies. • CAMOS initiated a study that has been funded on high intensity lasers. DOE support for CAMOS has been of central importance to the committee’s ability to continue to fulfill its mandate to the Board on Physics and Astronomy and to the wider atomic, molecular, and optical sciences research community.

Sheet-bulk metal forming is a new production process capable of performing deep-drawing and massive forming steps in a single operation. However, due to the high forming forces of the forming process, continuous process control is required in order to detect wear on the forming tool before production quality is impacted. To be able to measure the geometry of the forming tool in the limited space of forming presses, a new inspection system is being developed within the SFB/TR 73 collaborative research center. In addition to the limited space, the process restricts the amount of time available for inspection. Existing areal optical measurement systems suffer from shadowing when measuring the tool's inner elements, as they cannot be placed in the limited space next to the tool, while tactile measurement systems cannot meet the time restrictions for measuring the areal geometries. The new inspection system uses the fringe projection optical measurement principle to capture areal geometry data from relevant parts of the forming tool in short time. Highresolution image fibers are used to connect the system's compact sensor head to a base unit containing both camera and projector of the fringe projection system, which can be positioned outside of the moving parts of the press. To enable short measurement times, a high intensity laser source is used in the projector in combination with a digital micro-mirror device. Gradient index lenses are featured in the sensor head to allow for a very compact design that can be used in the narrow space above the forming tool inside the press. The sensor head is attached to an extended arm, which also guides the image fibers to the base unit. A rotation stage offers the possibility to capture measurements of different functional elements on the circular forming tool by changing the orientation of the sensor head next to the forming tool. During operation of the press, the arm can be travelled out of the moving parts of the forming press. To further reduce the measurement times of the fringe projection system, the inverse fringe projection principle has been adapted to the system to detect geometry deviations in a single camera image. Challenges arise from vibrations of both the forming machine and the positioning stages, which are transferred via the extended arm to the sensor head. Vibrations interfere with the analysis algorithms of both encoded and inverse fringe projection and thus impair measurement accuracy. To evaluate the impact of vibrations on the endoscopic system, results of measurements of simple geometries under the influence of vibrations are discussed. The effect of vibrations is imitated by displacing the measurement specimen during the measurement with a linear positioning stage. The concept of the new inspection system is presented within the scope of the TR 73 demonstrational sheet-bulk metal forming process. Finally, the capabilities of the endoscopic fringe projection system are shown by measurements of gearing structures on a forming tool compared to a CAD-reference. © 2015 SPIE. DFG/CRC/TR 73

This paper presents a new method to control the position of a micro-column snow target. This target enables the measurement of the mean electron density of the pre-plasma created by a pre-pulse with different time delays. This research will allow a better understanding of the generation of fast protons from the interaction between a structured pre-plasma and a high intensity laser.

Radiation reaction describes the classical self-interaction of charged particles with their radiation field. The theory will be reviewed, as well as interesting possibilities to test the theory in the near future with ultra-high intensity lasers.

Manipulation of laser pulses at high intensities is an important yet challenging issue. New types of plasma-based optical devices are promising alternatives to achieve this goal. Here we propose to modulate the polarization state of intense lasers based on oblique reflection from solid-plasma surfaces. A new analytical description is presented considering the plasma as an uniaxial medium that causes birefringence effect. Particle-in-cell simulation results numerically demonstrate that such a scheme can provide a tunable polarization control of the laser pulses even in the relativistic regime. The results are thus relevant for the design of compact, easy to use, and versatile polarization modulators for high-intensity laser pulses.

Most pure, organic liquids are remarkably transparent materials, even when exposed to high laser intensities. At very high laser intensities, however, ∼109–1010 W/cm2 and under the appropriate conditions, liquids can absorb extremely strongly due to the mechanism of multiphoton absorption, which results in ionization and dissociation of the liquid molecules. Strong absorption results in significant heating and temperature increases. Multiphoton absorption thus provides a new mechanism for heating otherwise transparent liquids. Furthermore, the thermal energy is deposited in a very thin layer near the surface of the liquid, which is much thinner than the classical penetration depth. A thermal model based on multiphoton absorption is developed, and results are presented for heating liquid water with laser pulses from the popular Nd: YAG laser at a wavelength of 266 nm.

The research and technical achievements in the area of lasers are summarized every three years by the National Symposium on Laser Technology held in the Baltic See Resort ś winoujście near Szczecin, Poland. The paper presents a review of the main symposium subjects tracks debated during this key national laser event in September 2012. There are shown development tendencies of laser materials and technologies and laser associated branches of optoelectronics in this country, including the efforts of academia, governmental institutes, research businesses and industry. The symposium work are divided to two branches: development of lasers and laser applications, where the laser systems operators and laser users present their achievements. Topical tracks of the meeting are presented, as well as the keynote and invited subjects delivered by key representatives of the laser industry. The STL 2012 was a jubilee meeting held for the Xth time.

Ultra-intense lasers generate filaments that can be used not only for the analysis of the atmosphere (multi-pollutant Lidar) but also for its control, e.g. laser induced lightning triggering and water cloud condensation. 150-word Biography: After having lead research projects at the ETH-Lausanne and the University Berlin and being a Professor at the University Lyon and visiting Professor at Yale University, Prof. J.P. Wolf joined the University of Geneva in 2005. Since then he set up a new team at the Group of Applied Physics (GAP), dedicated to the biomedical and atmospheric applications of ultrashort lasers (www.gap.unige.ch/biophotonics). He now concentrates his research activities on coherent control of biological systems, advanced non-linear microscopy and imaging of living cells and applications of laser filamentation to atmospheric diagnostics and control. He was awarded an ERC Advanced Grant in 2011, the Prix La Recherche 2005, the Grand Prix de Physique de l’Academie des Sciences 2002, and the Technology Award of the Land Berlin-Brandenburg in 1993. He is member of the Institut Universitaire de France since 1996 and NATO Senior Fellow. Article not available.

Laser technology has been in the scope of dentistry community since Stern & Sognnaes (1964) studied laser application on dental hard tissues. Lasers have become an attractive instrument for many dental procedures including soft tissues surgery (Sperandio et al., 2011), decontamination (Benedicenti et al., 2008; Koba et al., 1998) and for assuring antiinflammatory effects (Lang-Bicuto et al., 2008). In restorative dentistry, laser has been used successfully for cavity preparation (De Moor et al., 2010; Obeidi et al., 2009), caries prevention (Namoour et al., 2011; Rechmann et al., 2011; Zezell et al., 2009), caries decontamination (Namour et al., 2011) and caries removal (Neves et al., 2011; White et al., 1993). For that, high intensity lasers are indicated, which are able to promote controlled temperature rise in a small and specific area of dental hard tissue (Ana et al., 2007). Depending on the temperature rise and the interaction of laser irradiation with dental tissues, it is possible to produce specific micro structural and/or mechanical changes related to a correct clinical application.

Several X-ray laser schemes which have possibilities for extending the present X-ray lasing wavelengths to shorter regions are reviewed. Some of these schemes may be worth reinvestigation using the ultrashort pulse, high intensity lasers that are available at present or in near future.

I promised to talk about the futurology of high intensity lasers. That was an unwise decision on my part. I find that every talk that has been given here is on futurology, whether it is admitted or not.

The temporal contrast is classified into two main regimes, the nanosecond-scale and the picosecond-scale contrast prior to the main pulse. The Lund terawatt laser system is shown to be improved on the nano- and picosecond-scale by a factor of 10 and 50, respectively, when it was optimized for contrast but not for energy. Calculations are also presented to emphasize the role of angular dispersion on the picosecond contrast. Finally we show a compromise between the duration and contrast of femtosecond laser pulses amplified in an optical parametric (chirped pulse) amplifier.

This tutorial will review the development of ultrafast high-intensity lasers and the technologies that make them possible. Topics will include a review of ultrashort pulse oscillators, control of high-order dispersion and spectral reshaping, selection of ultrafast compatible optical materials and components, management of thermal distortions and beam quality, and development of new pulse measurement and characterization technologies. A brief review of future systems including those being designed to reach petawatt peak powers with single-Hz repetition rates and terawatt peak powers at kHz repetition rates will also be presented.

There has been much progress in the development of high intensity lasers and in the science of laser driven inertially confined fusion such that ignition is now a near term prospect. This lecture reviews the field with particular emphasis on areas of my own involvement.

Elucidation of the mechanisms of laser damage is indispensable in realizing high resistance mirrors for the next generation of ultra-short pulse high intensity lasers. In this study, the surface and a section of the laser-damaged area of a laser mirror were observed with a laser microscope and a transmission electron microscope (cross-sectional TEM), respectively. A grain boundary of HfO2 microcrystal was observed in the damaged area. This observation and an evaluation of the mirror's damage resistance showed that the formation of crystals in the multilayer mirror is one of the major determinants of damage resistance.

In this special session, we discuss global climate change concerns, as well as cleanup of wastes and/or toxic materials, their relations to energy and other technologies. We especially bring together scientists to discuss available and/or developable technologies of amelioration or cleanup, for consideration of unusual uses of Lasers, Particle Beams and other plasma Phenomena.

We present the results of a series of impedance‐match experiments using copper‐aluminum targets irradiated using the Janus Laser Facility. The results are compared to extrapolations of data obtained at lower pressures using impact techniques. The sources of errors are described and evaluated. We discuss the potential of lasers for high accuracy equation‐of‐state investigations.

We propose and demonstrate a method for shaping the focus of high intensity lasers into an annular or “donut” mode. The method, based on helical phase plates, has been implemented at the PHELIX laser facility.

In the last fifteen years stimulated Raman backscattering (SRBS) in plasma has been intensively elaborated as a promising tool on the way towards high intense lasers. There are several advantages of this technique in comparison to the world-wide used the CPA-Chirped Pulse Amplification technique for a laser amplification. We present the principle of the SRBS technique, the best results so far obtained in theory and experiment, and a possible SRBS project at the PALS Research Centre in Prague.