Автоматическое закорачивание отдельных фаз линий для ликвидации дуговых коротких замыканий

During the last few years high power diode laser arrays have become well established for direct material processing due to their high efficiency of more than 50%. But standard broad-area waveguide designs are susceptible to modal instabilities and filamentations resulting in low beam qualities. The beam quality increases by more than a factor of four by using tapered laser arrays, but so far they suffer from lower efficiencies. Therefore tapered lasers are mainly used today as single emitters in external resonator configurations. With increased output power and lifetime, they will be much more attractive for material processing and for pumping of fiber amplifiers. High efficiency tapered mini bars emitting at a wavelength of 980 nm are developed, and in order to qualify the bars, the characteristics of single emitters and mini bars from the same wafer have been compared. The mini bars have a width of 6 mm with 12 emitters. The ridge waveguide tapered lasers consist of a 500 µm long ridge and a 2000 µm long tapered section. The results show very similar behavior of the electro-optical characteristics and the beam quality for single emitters and bars. Due to different junction temperatures, different slope efficiencies were measured: 0.8 W/A for passively cooled mini bars and 1.0 W/A for actively cooled mini-bars and single emitters. The threshold current of 0.7 A per emitter is the same for single emitters and emitter arrays. Output powers of more than 50 W in continuous wave mode for a mini bar with standard packaging demonstrates the increased power of tapered laser bars

Формирование предпринимательских умений студентов инженерного вуза

Представлена методика формирования предпринимательских умений студентов инженерного вуза на основе практико-ориентированной подготовки, способствующей внедренческой деятельности инженера в современных условиях. Проведен анализ состояния проблемы формирования предпринимательских умений в России. Определены педагогические условия, способствующие формированию готовности студентов технического университета к комплексной инженерной деятельности. Сформулировано понятие предпринимательской компетенции инженера. Обосновано эффективное применение метода проектов для формирования предпринимательских умений студентов инженерного вуза. Представлена модель формирования предпринимательских умений студентов инженерного вуза с учетом проектной деятельности инженера.The developing methods of entrepreneurial competences of engineering students, based on the practice-oriented training to encourage an implemental activity of an engineer in the modern context has been presented in the report. The analysis of the problem of entrepreneurial competencies development in Russia has been carried out. The pedagogical conditions encouraging the commitment of the technical university students for an integrated engineering activity has been defined. The concept of entrepreneurial competencies of an engineer has been stated. An effective appliance of project methods to develop entrepreneurial competences of the engineering university students has been proved. There has been presented the development model of entrepreneurial competences of engineering students

Spin and Orbital Polarization in Layered Rare Earth-Manganese Ternary Intermetallic Compounds.

Abstract not availableJRC.E-Institute for Transuranium Elements (Karlsruhe

5 W high-efficiency high-brightness tapered diode lasers at 980 nm

Tapered diode lasers in external resonator configuration are suitable for applications such as frequency conversion or non-linear spectroscopy were narrow linewidth in combination with high output power is needed. In order to increase the brightness it is necessary to make the output power and the efficiency comparable to broad area lasers and simultaneously keep the beam quality nearly diffraction limited. For this purpose we have grown low modal gain, single quantum well InGaAs/AlGaAs devices emitting at 980 nm by molecular beam epitaxy. As an example of a tapered laser with an overall length of 3.5 mm, we achieved an optical output power of more than 5 W in continuous wave mode (cw)

Ресурсоэффективность и ее особенности в области информационных технологий

This article discusses features and classification of resources, with special emphasis on economic information resources, relationship between the concepts of effect and efficiency, as well as calculation the total and comparative effectiveness; the definition of resource efficiency in the broadest sense is given, and key context notions are defined; features of resource efficiency in the field of information technology are considered

5 W frequency stabilized 976 nm tapered diode laser

More and more applications, like tunable frequency doubling of diode lasers for blue-green outputs, non linear spectroscopy, or pump laser sources for fiber lasers necessitate diffraction-limited tunable narrow linewidths and high output powers in the multiwatt regime. For these applications, tapered lasers based on a tapered amplifier with gain-guided design can be used in an external cavity set up to guarantee both - frequency stabilization and tunability. We have realized frequency stabilized high-power ridge-waveguide tapered diode lasers with more than 4W of cw output power. These low modal gain, single quantum well InGaAs/AlGaAs devices emitting between 920nm and 1064nm were grown by molecular beam epitaxy. Tapered single emitters consist of an index-guided ridge section and a gain-guided taper section with an overall length of 3.5mm. The taper angle was 6°. With a high-reflectivity coating on the rear facet and an antireflection coating on the front facet more than 10W of output power have been demonstrated. To optimize the beam quality at higher output power the two different sections have been operated by different operation currents. For this purpose the tapered diodes have been mounted p-side down on structured submounts. For wavelength tunability and frequency stabilization the tapered diodes, provided with AR coatings on both facets, have been used in external cavity setup in Littrow configuration. The influence of the different operation currents on the electro-optical and beam characteristics has been carefully investigated in detail. Within this operation mode a nearly diffraction limited behavior up to 5W has been established

Developments in tapered lasers at 980 nm to 1060 nm

High-brightness diode lasers are attractive for pumping of fiber lasers, raman amplification and other applications. The paper gives an overview about the development and current status of tapered high-brightness diode lasers