IPG Photonics

About: IPG Photonics is a based out in . It is known for research contribution in the topics: Laser & Fiber laser. The organization has 903 authors who have published 1241 publications receiving 63339 citations.

High Power Processing Fiber Cable with Integrated Beam Expander and Method of Use

Abstract: The present disclosure is a system for the protection of a fiber within a laser system. The system has a water-cooled housing supporting a termination block, which is operative to shield a protective layer of a delivery fiber from back-reflected beams of light. The termination block is manufactured from quartz and is frustconical in configuration and fuseable to the delivery fiber. The delivery fiber has a polymeric protective layer with an acceptance end and a delivery end, and passes through a washer contained within the housing; the washer has a dielectric reflective coating. The system has at least one terminal block connector which further comprises a cone termination block, a reflector, and a set of light guards. The cone termination block is spliced to an output end of the delivery fiber and produces an angle λ so as to reduce propagation of back-reflected light. The reflector is positioned so as to block additional back-reflected light from the protective layer of the delivery fiber.

Tuned in to the Earth … from the school EduSismo: the French educational seismological network

Abstract: Earthquakes are both troubling and fascinating because of their suddenness, the terrible destruction they can wreak and because they still remain unpredictable. This is why emphasis must be placed on preparation, especially in the school system where causes and effects of these hazards are studied. But trying to explain earthquakes, scrutinizing the earth's depths, taking on the planet internal dynamics... entail moving into the inaccessible. In this respect seismology is a source of complexity and fascination. Scientific culture is thus at the heart of seismic risk instruction. All of this is in what the "SISMOS a l'Ecole" curriculum is involved, by implementing an educational program that allows a natural risk culture to be engaged through a scientific and technological approach. The original and innovative aspect of this programme stems from giving students the opportunity to install a seismometer in their school. The recorded signals, reflecting regional or global seismic activity, feed into an on-line database, a genuine seismic resource centre and a springboard for educational and scientific activities. The network 'EduSismo' (numbering some sixty stations installed in metropolitan France, the overseas departments and territories and a few French high schools abroad) is the outgrowth of an experiment conducted in the Alpes-Maritimes area some twelve years back. Since then, the programme implemented has gone beyond simply acquiring seismic signals, which has been procured by research and monitoring centres. By appropriating a scientific measurement, the student becomes personally involved and masters complex concepts about geophysics and geosciences. The development of simple devices and the design of concrete experiments associated with an investigative approach make it possible to instill the students, these future citizens, a high-quality scientific culture and an education about risks. Today, this programme is expanding. New initiatives with Italian, British and Swiss partners are being put in place to share experiences and data in Europe.

Sub-nanosecond broad spectrum generating laser system

Abstract: The present invention provides systems and methods for producing short laser pulses that are amplified and spectrally broadened in a bulk gain media. The bulk material, having laser gain and nonlinear properties, is concurrently exposed to an optical pump input and a seed input, the pump power being sufficient to amplify and spectrally broaden the seed pulse.

Wavelength tunable, single-longitudinal-mode optical parametric oscillator with a transversally chirped volume Bragg grating.

Abstract: We report on single-longitudinal-mode (SLM) operation of a low-threshold optical parametric oscillator, with a 17 nm tunability near 2 µm. The oscillator uses a MgO:PPLN crystal in Type 0 quasi-phase-matching configuration, pumped by a 1.064 µm SLM laser. Despite the huge acceptance bandwidth near-degeneracy of MgO:PPLN, spectral selection down to a SLM is achieved by combining a volume Bragg reflector and Vernier filtering in nested signal and idler cavities. Tunability over 17 nm is demonstrated owing to a transverse chirp of the grating period of the Bragg reflector.

Can irregularities of solar proxies help understand quasi-biennial solar variations?

Abstract: . We define, calculate and analyze irregularity indices λISSN of daily series of the International Sunspot Number ISSN as a function of increasing smoothing from N = 162 to 648 days. The irregularity indices λ are computed within 4-year sliding windows, with embedding dimensions m = 1 and 2. λISSN displays Schwabe cycles with ~5.5-year variations ("half Schwabe variations" HSV). The mean of λISSN undergoes a downward step and the amplitude of its variations strongly decreases around 1930. We observe changes in the ratio R of the mean amplitude of λ peaks at solar cycle minima with respect to peaks at solar maxima as a function of date, embedding dimension and, importantly, smoothing parameter N. We identify two distinct regimes, called Q1 and Q2, defined mainly by the evolution of R as a function of N: Q1, with increasing HSV behavior and R value as N is increased, occurs before 1915–1930; and Q2, with decreasing HSV behavior and R value as N is increased, occurs after ~1975. We attempt to account for these observations with an autoregressive (order 1) model with Poissonian noise and a mean modulated by two sine waves of periods T1 and T2 (T1 = 11 years, and intermediate T2 is tuned to mimic quasi-biennial oscillations QBO). The model can generate both Q1 and Q2 regimes. When m = 1, HSV appears in the absence of T2 variations. When m = 2, Q1 occurs when T2 variations are present, whereas Q2 occurs when T2 variations are suppressed. We propose that the HSV behavior of the irregularity index of ISSN may be linked to the presence of strong QBO before 1915–1930, a transition and their disappearance around 1975, corresponding to a change in regime of solar activity.