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

Montage nichtlinearer optischer Kristalle für den Einsatz in der Luft- und Raumfahrt

By means of a space-based LIDAR-system (Light Detection and Ranging), a global analysis of gases in the atmosphere such as water vapor, methane or CO2 can be carried out. The understanding of the processes in the atmosphere can be improved by an extensive database. Thereby a revision and correction of the climate models and therefore a precise prediction would be enabled. Thermal and mechanical load requirements are particularly high during space operation. Thereby questions concerning reliability at operating times of at least three years without loss in pulse energy and beam quality are of special importance. Even though simple systems are already in orbit, an advancement of critical components in complex systems is required. The investigation of the mounting of optical components is carried out by means of a specially designed furnace. Thereby several strategies are considered. The offset strategy proves suitable for mounting tolerance-insensitive components. In combination with a local cooling the tolerances fall below the required 100 µrad. The joining of non-linear crystals using solder is hindered by different CTE’s along different crystal axes. The BBO-crystal is crack-sensitive due to its mechanical properties. For the joining, a suitable combination of material and structure can be found and the resulting combination can be demonstrated by an example of a functional Pockels cell. Thereby it is shown that the boundary conditions concerning electrical contacting and high voltage isolation are fulfilled simultaneously. Joining LBO-crystals is less critical than joining BBO-crystals due to the differences in mechanical properties.For an efficient frequency conversion, the temperature distribution within the LBO-crystal has to be homogeneous. For this reason the crystal is soldered planar. The conversion efficiency at 67% is at the level of presently used clamped systems. For the investigation of the technical suitability of the soldering technology for assembling TGG-crystals, polarization measurements are used. Here it becomes evident that the path difference R is smaller for soldered crystals than for glued crystals. The distribution along the crystal facet is more homogeneous. Both are advantageous for the properties of optical isolators. The KTP-crystal is mounted between two heater bars, similar to the mounting of the LBO-crystal. Both the investigation of the mechanical stability of the KTP-crystal after the temperature cycling test and the analysis of the optical properties show the technical applicability of the soldering technology. During the optical tests a non-soldered and a soldered KTP-crystal are compared. The deviation of optical performance POpt of both analyzed KTP-crystals is within the tolerance accuracy. In the future, mounting of non-linear crystals by means of solder enables the realization of completely soldered laser systems. Thereby the vibration-sensitive clamping or outgassing gluing technique can be dispensed. In comparison to gluing, soldering additionally offers a substantial higher thermal and electrical conductivity. Both the performance and the rated service time of the instruments can be increased. Besides the higher mechanical stability, the solder technique offers the advantage of the re-melting of the join. The already soldered optical component can be readjusted. During the soldering process a combination of solders with different melting points can increase the mechanical stability of the assembly and simplify the mounting of the laser system