Врахування вітчизняних умов при використанні закордонних Z-моделей прогнозування банкрутства

The green cw laser presented in this work is realized by means of a Pr:YLF crystal emitting at 523 nm that is pumped by a blue GaN laser diode in an extremely short resonator. With a 500 mW-diode a laser has been achieved with M2 = 1, a slope of 40 % and an output power of 140mW with an absorbed pump power of 410 mW which results in an electrooptical efficiency of 6.5 %. Despite the reduced overlap with a 1 W-diode the output power rises to 290 mW with an absorbed pump power of 850 mW and the M2 increases only slightly. Based on these results a compact laser package has been accomplished using a monolithic micro optics for the beam shaping of the diode light and joining all components with a low-shrinkage adhesive on a common base plate. In a first test of the alignment strategy a laser with an output power of 92 mW has been achieved by means of the 500 mW pump power

Некоторые результаты применения метода геометрического анализа дизъюнктов для поисков смещенного крыла пласта в Прокопьевском районе Кузбасса

In this paper we present the development of a compact, thermo-optically stable and vibration and mechanical shock resistant mounting technique by soldering of optical components. Based on this technique, new generations of laser pump sources for aerospace applications are designed. In these laser systems the used soldering technique replaces the glued connection between the optical component and its join partner. The main challenges are the alignment accuracy in the arc second range and the realization of the long term stability of every single part in the laser system (e.g. resonator mirrors)

О необходимости прослеживания Балейско-Дарасунского разлома в пределах Борщевочного кряжа

In this paper we present the development of a compact, thermo-optically stable and vibration and mechanical shock resistant mounting technique by soldering of optical components. Based on this technique a new generation of laser sources for aerospace applications is designed. In these laser systems solder technique replaces the glued and bolted connections between optical component, mount and base plate. Alignment precision in the arc second range and realization of long term stability of every single part in the laser system is the main challenge. At the Fraunhofer Institute for Laser Technology ILT a soldering and mounting technique has been developed for high precision packaging. The specified environmental boundary conditions (e.g. a temperature range of -40 °C to +50 °C) and the required degrees of freedom for the alignment of the components have been taken into account for this technique. In general the advantage of soldering compared to gluing is that there is no outgassing. In addition no flux is needed in our special process. The joining process allows multiple alignments by remelting the solder. The alignment is done in the liquid phase of the solder by a 6 axis manipulator with a step width in the nm range and a tilt in the arc second range. In a next step the optical components have to pass the environmental tests. The total misalignment of the component to its adapter after the thermal cycle tests is less than 10 arc seconds. The mechanical stability tests regarding shear, vibration and shock behavior are well within the requirements

Моделирование уравнений проекционного осциллографирования на машине "ЭМУ-10"

The passive-alignment-packaging technique presented in this work provides a method for mounting tolerance-insensitive optical components e.g. non-linear crystals by means of mechanical stops. The requested tolerances for the angle deviation are ±100 µrad and for the position tolerance ±100 µm. Only the angle tolerances were investigated, because they are more critical. The measurements were carried out with an autocollimator. Fused silica components were used for test series. A solder investigation was carried out. Different types of solder were tested. Due to good solderability on air and low induced stress in optical components, Sn based solders were indicated as the most suitable solders. In addition several concepts of reflow soldering configuration were realized. In the first iteration a system with only the alignment of the yaw angle was implemented. The deviation for all materials after the thermal and mechanical cycling was within the tolerances. The solderability of BBO and LBO crystals was investigated and concepts for mounting were developed

Investigation of LPBF A800H steel parts using Computed Tomography and Mössbauer spectroscopy

© 2020 Elsevier B.V. Laser powder bed fusion (LPBF) was applied in this study to produce a prototype of a miniaturized catalytic burner (CAB), which is a key component of high-temperature polymer electrolyte fuel cells. This prototype was characterized by its complex design with numerous channels, chambers, and thin walls. The test samples and CAB prototype were made of a heat-resistant, anti-corrodible steel called “Alloy 800H” (1.4876), a material that poses problems for welding operations and especially for the LPBF process due to its strong susceptibility to hot cracking and spatters. The effects of LPBF parameter variation on preliminary test samples were investigated by nano-focus Computed Tomography (CT) and Optical microscopy to clarify the internal structure and defects for further LPBF process optimization. Mössbauer spectroscopy points out that LPBF process does not lead to either local phase separation nor oxidation of steel, which is critical factor for use of CAB at high temperatures. The sufficient LPBF parameter sets were used to manufacture the CAB prototype, which was examined by micro-CT and optics as well. The main result of the investigation is a demonstration of the technological feasibility to decrease the number and size of defects in complex LPBF-manufactured Alloy 800H constructions without changes in phase composition at high temperatures

Verfahren zur Modenbeeinflussung von optischer Strahlung in einem Medium

The invention relates to a method for influencing the mode of laser radiation propagating in a medium (9). In the method, before the medium (9) is used, the index of refraction is modified in a plurality of volume areas (21) within the medium (9) by laser pulses for which the medium (9) is transparent, by adjusting the intensity of the laser pulses locally in said volume areas (8) to a value at which non-linear absorption occurs in the medium (9). To this end, the selected volume areas (21) are spaced apart from one another in the direction of propagation and/or obliquely with respect to the direction of propagation of the optical radiation. The method according to the invention can be used to easily and cost-effectively influence the modes of the optical radiation propagating in the medium, without having to use additional optical elements with additional adjustment complexity for this purpose