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Driven by developments in the automotive industry, the availability of compact consumer-grade LiDAR (Light Detection and Ranging) sensors has increased significantly in recent years. Some of these sensors are also suitable for UAV-based surveying tasks. This paper first discusses the differences between consumer-grade and survey-grade LiDAR systems. Special attention will be paid to the scanning mechanisms used on the one hand and to different solutions for the transceiver units on the other hand. Based on the technical data of two concrete systems, the consumer-grade DJI Zenmuse L1 sensor and the survey-grade scanner RIEGL VUX-1UAV, the expected effects of the sensor parameters on the 3D point cloud are first discussed theoretically and then verified using an exemplary data set in Hessigheim (Baden-Württemberg, Germany). The analysis shows the possibilities and limitations of consumer-grade LiDAR. Compared to the low-cost sensor, the high-end scanner exhibits lower range measurement noise (5–10 mm) and better 3D point location accuracy. Furthermore, the higher laser beam quality of high-end devices (beam divergence, beam shape) enables more detailed object detection at the same point density. With moderate accuracy requirements of 5–10 cm, however, applications in the geodetic-cartographic context also arise for the considerably less expensive consumer-grade LiDAR systems. [ABSTRACT FROM AUTHOR]

The most commonly used surface protection technologies against wear and corrosion are electrochemical hard chromium plating or thermal spraying. But these coating technologies have limits. Additionally, due to health concerns, hard chromium plating is under increasingly restrictive use in Germany, the European Union, and the Asian market. One technology which is currently under investigation for replacing conventional coating processes, e.g., plating in these instances is the high-speed laser cladding. Using high-speed laser cladding (high-speed laser metal deposition, HS-LMD), which is a DED (directed energy deposition) process, a laser beam is heating powder particles, which are fed coaxially into the laser beam, to nearly melting temperature before these particles hit the surface. Using a laser as the heat source, the heat input into the workpiece can be minimized. This allows a very low dilution of additive material into workpiece--typically < 10 µm--and high feed rates between 100 and 500 m/min can be achieved. Layers generated by this process can be locally adjusted in thickness between 50 and 300 µm per layer. Since each layer is metallurgically bonded to the metallic substrate or the adjacent layer before, multi layers or multi-material approaches are feasible. By use of the aforementioned unique process features, new and in properties tailored coating systems become possible. HS-LMD might be a promising candidate for replacement of hard chromium plating, for example, large rotational symmetric parts. In this paper, we have selected Rockit®401 as a hard, corrosion-resistant, and nearly "cracking-proof" material. Additionally, we have chosen the corrosion resistant Inconel® 625. We will investigate the influence of high surface rates on properties such as defects, hardness, and crack susceptibility, as well as achievable layer thicknesses. [ABSTRACT FROM AUTHOR]

The European X-ray Free-Electron Laser Facility in Germany delivers x-ray pulses with femtosecond pulse duration at a repetition rate of up to 4.5 MHz. The free-electron laser radiation is created by the self-amplified spontaneous emission (SASE) process, whose stochastic nature gives rise to shot-to-shot fluctuations in most beam properties, including spectrum, pulse energy, spatial profile, wavefront, and temporal profile. Each spectrum consisting of many spikes varies in width and amplitude that appear differently within the envelope of the SASE spectrum. In order to measure and study the SASE spectrum, the HIgh REsolution hard X-ray single-shot (HIREX) spectrometer was installed in the photon tunnel of the SASE1 undulator beamline. It is based on diamond gratings, bent crystals as a dispersive element, and a MHz-repetition-rate strip detector. It covers a photon energy range of 3 keV–25 keV and a bandwidth of 0.5% of the SASE beam. The SASE spikes are resolved with 0.15 eV separation using the Si 440 reflection, providing a resolving power of 60 000 at a photon energy of 9.3 keV. The measured SASE bandwidth is 25 eV. In this paper, we discuss the design specifications, installation, and commissioning of the HIREX spectrometer. The spectral results using Si (110), Si (111), and C (110) crystals are presented. [ABSTRACT FROM AUTHOR]

Purpose: To characterize the clinical presentation and outcome of patients with vaginal intraepithelial neoplasia (VAIN).Methods: Medical records of 65 women with VAIN treated between 2005 and 2012 at the colposcopy clinic of a German university hospital were retrospectively evaluated for VAIN grade, HPV status, VAIN localization, treatment method and relapse rate. Follow-up data were available for 53 patients (82 %).Results: Mean age was 61 years (range 32-89 years). Most lesions (55 %) were found in the upper vaginal third; 42 % were multifocal. Multifocal VAIN was more frequently HPV positive than single lesions (p = 0.059). Of all women with known HPV status, 83 % were high-risk (HR) HPV positive and 32 % had a simultaneous CIN earlier or at the same time as the VAIN, mostly CIN 3 (66 %). Two-thirds had a hysterectomy in the past, often because of high-grade CIN. Most cases of VAIN were treated with CO2 laser vaporization. A relapse of the disease could be confirmed for 57 %. HR-HPV positive VAIN was significantly more likely to relapse than HR-HPV negative VAIN (p = 0.005). There were three cases of vaginal cancer with surrounding VAIN 3 or vaginal cancer diagnosed after primary treatment of VAIN 3 and one case of vaginal cancer during follow-up 22 months after the first laser vaporization. All of these cases were HR-HPV positive.Conclusions: VAIN has a high relapse rate and a high progression rate to invasive cancer especially if HR-HPV positive. Therefore, adequate follow-up examinations are mandatory. [ABSTRACT FROM AUTHOR]

Abstract: An active landslide, affecting a composite sea cliff section of the island of Rügen, Germany was investigated and monitored using terrestrial laser scanning. Biannual surveys were performed from 2006 to 2011. High resolution scans were used to delineate landslide extensions, monitor the spatial and temporal changes, and evaluate the processes of mass wasting along the cliff section. Between May 2006 and May 2011 the multi-temporal analysis documents a strong landward progression of the landslide that resulted in an increase in the planimetric area by 32%. In the same period, 9365m3 of soil volume has been removed primarily due to rainfall triggered surface runoff erosion and the resulting slumping. This volume loss correlates with the preferential erosion of weak and unconsolidated sediments building up the major part of the cliff face. This produced a maximum cliff top retreat of 17.32m with an average retreat rate of 3.46myr−1. The quantification of the mass wasting processes and cliff top retreat demonstrates the substantial effect of local cliff lithology on slope stability, and supports a prognosis of the near future development of the landslide. Furthermore, the absence of local wave attack indicators or human activity highlights the major role of subaerial processes in the erosion of the sea cliff. These results can be transferred to cliff locations in the urbanised cliff top area nearby that currently suffer similar cliff erosion processes and episodic events of large cliff top retreats. The study therefore provides reliable data for the local authorities in charge of hazard assessment and planning and implementation of adaptive countermeasures. [Copyright &y& Elsevier]

Results of international bilateral supplementary comparisons of the Russian and German national standards of the unit of average laser power carried out from 2009 to 2012 are presented. [ABSTRACT FROM AUTHOR]

Abstract: The thermo-physical characteristics of both nuclear, industrial graphite, such as MPG-6 from NIIGRAFIT or SGL composite from SGL Carbon Group, and the first synthesized graphite composite based on a carbon 13С isotope have been measured from room temperature to 1675K by laser flash method on an LFA-427 setup from Netzsch (Germany). The results obtained are compared to the previous data of X-Ray analysis and high-resolution electron microscopy and can be used in thermal calculations of the design of a neutron converter graphite target. [Copyright &y& Elsevier]

Background: Stone baskets could be easily destroyed by Holmium:YAG-laser at an endourologic treatment, with respect to this, we try to improve the resistance by coating them with a titanium oxide layer. The layer was established by a sol-gel-process. Materials and methods: Six new baskets (Equadus, Opi Med, Ettlingen, Germany) were used: 1.8 Ch. with 4 wires (diameter 0.127 mm). Three baskets were coated with a layer of titanium oxide established by a sol-gel process at the BioCerEntwicklungs GmbH in Bayreuth (~100 nanometres thickness). The lithotripter was a Holmium:YAG laser (Auriga XL, Starmedtec, Starnberg, Germany). 10 uncoated and 10 coated wires were tested with 610 mJ (the minimal clinical setting) and 2 uncoated and 2 coated wires were tested with 110 mJ. The wires were locked in a special holding instrument under water and the laser incident angle was 90°. The endpoint was gross visible damage to the wire and loss of electric conduction. Results: Only two coated wires resisted two pulses (one in the 610 mJ and one in the 110 mJ setting). All other wires were destroyed after one pulse. Conclusion: This was the first attempt at making stone baskets more resistant to a Holmium:YAG laser beam. Titanium oxide deposited by a sol-gel-process on a titanium-nickel alloy did not result in better resistance to laser injuries [ABSTRACT FROM AUTHOR]

Abstract: One of the main objects of the international standard IEC 60825-1 is to protect persons from laser radiation. In addition to engineering measures, the appointment of a Laser Safety Officer (LSO) is certainly one of the most important administrative measures as far as the safe use of lasers is concerned. It should be the Laser Safety Officer''s duties to review several protective measures and designate the appropriate controls to be implemented. Due to the associated increased risk, the LSO is recommended for operation of laser class 3B and 4 in most national regulations. In Germany the accident insurance regulations take precedence over recommendations in a technical standard, and the duties of an LSO have been mandatorily fixed for many years. In principle the appointment of an LSO and his/her respective duties and responsibilities are a matter for national regulations and might therefore differ from country to country, being in some cases either more or less. Therefore, the Artificial Optical Radiation Directive 2006/25/EC will alter the current situation in the near future due to the fact that this directive has to be transposed into the national regulations of all 27 member states of the European Union. It will take into account the minimum health and safety requirements regarding the exposure of workers. Since the LSO is not even mentioned in the directive, the laser community has been worried that the approved functions of an LSO might be lost. This fear seems to have been groundless especially in Germany, since the current draft of an ordinance on optical radiation at the workplace specifies the need for an LSO. The area of responsibility shall include, in addition to laser class 3B and 4, all other optical radiation sources with comparable hazard potential but because the respective duties are not yet clearly defined, there are somewhat conflicting opinions. In the discussion, it is mainly the required degree of competence or expertise and the modalities of qualification and certification that are the points of concern. This is especially noteworthy because of the long-standing accident prevention regulations and evidently different views between the accident insurance and the Federal Ministry. In addition to the description of the various strategies, the pros and cons are critically described and challenged in order to preserve the existing high level of safety which is connected with the appointment of an LSO. [Copyright &y& Elsevier]

Feasibility studies on applying laser radiation for the removal of superficial deposits from historic glass are being carried out within a three-year interdisciplinary project in Germany. Previous investigations revealed that there is insufficient knowledge about interaction processes between UV-laser radiation and individual surface layers of encrusted historic glass. therefore, detailed studies were first carried out on special model glass samples to simulate different stages in the corrosion of historic glass. The potential of UV-lasers for removing crusts and biolayers, as well as layers of various conservation materials (due to previous conservation work) is examined. It is of great importance to avoid damage to materials such as gel layers, paint layers or the glass itself. A KrF-excimer laser operating at λ = 248nm is used for the experiments. A mask projection technique is applied for irradiation. A modified optical set-up has been designed, using cylindrical lenses for large-area removal by 'line scanning'. Removal rates and thresholds for the materials mentioned above are monitored. The collected date enable comparison and evaluation of the feasibility of removing superficial layers from historic glass artifacts. The results indicate that in some cases a closed loop process control will be necessary to avoid over-cleaning. [ABSTRACT FROM AUTHOR]

Discusses the results of the first experiments with the free-electron lasers at the TESLA test facility at the high-energy physics research center in Hamburg, Germany. Strength of absorption of the laser radiation by atomic clusters; Nonlinear optical interaction between light and matter at ultraviolet wavelengths.

Focuses on the atom lasers demonstrated by scientists at the University of Munich and National Institute of Standards and Technology (NIST) from Bose-Einstein condensation in rubidium. How the scientists at Munich produce BEC and extract the atoms from the condensate; Estimated brightness of Munich's atom laser beam; Information on the NIST quasi-continuous atom lasers.

The article offers information regarding a sheet of intense laser light that can act as a trampoline as shown by researchers in Germany.

Abstract: We present results of damage studies performed at the Free-Electron LASer in Hamburg (FLASH) on amorphous carbon (a-C). The experiment was performed in the total external reflection geometry representing the working configuration of X-ray mirrors. The 177eV photon laser beam was focused on a 40nm thin layer of a-C coated on a silicon substrate. Single-shot damages were produced at two different grazing angles (4.3° and 7.7°) below the critical angle (θ c=8°) calculated for this photon energy. The corresponding damage fluence thresholds were determined to be 43.7 and 74mJ/cm2. No evidence of delamination or mechanical damages (cracks) under grazing angles on the 40nm thin sample was observed. The results are compared with the results of the previous experiment done on thicker layers (900nm) of a-C with the same experimental conditions . [Copyright &y& Elsevier]

Abstract: The Free Electron Laser at Hamburg (FLASH) facility at the Deutsches Elektronen-Synchrotron (DESY) is a linear accelerator that is operated in superconducting technology and produces soft X-ray laser light from 4.5 to 47nm. Several switching mirrors, located in the experimental hall, provide different beam lines with laser light, where the switching procedure lasts up to 1h and is performed at intervals of days or sometimes weeks. Since the experiments would be sufficient even with a lower repetition rate of the beam, a new kind of switching mirror has been invented. In this paper, the design and implementation of a fast switching mirror at FLASH are presented where focussed and unfocussed beam trains can be distributed between two beam lines with a frequency of up to 2.5Hz. The challenge lies in the precise repetition accuracy of position (few μm) and angle (about 1arcsec) of the mirror. In addition, first measurements taken at FLASH are analyzed and they show only little influence of the developed switching mirror on the beam position. [Copyright &y& Elsevier]

The article offers information on the Digital Scanned Laser Light Sheet Fluorescence microscopy (DSLM) developed by researchers at the European Molecular Biology Laboratory in Germany. The DSLM scans vertically through specimens with a µm wide beam of laser light, only exciting the fluorescent proteins briefly. This technique will greatly lessen photo-toxicity effects seen using other fluorescence microscopy methods that can damage developing organisms, affecting experimental results.

The article reports on the addition of delay in varying a beam of laser light on running delay. When three lasers in a row shine into one another, they can forge a connection in which the intensities of the first and last lasers vary in unison. It stated that the variation of one, lag those of the other by the amount of time it takes to pass between them. On the other hand, according to Wolf Singer, a neuroscientist at the Max Planck Institute for Brain Research in Frankfurt, Germany, the experiment help decipher the synchronization of nerve signals in the brain.