144 research outputs found
Structuring of sapphire by laser-assisted methods, ion-beam implantation, and chemical wet etching
Sapphire is an attractive material for micro- and opto-electronic systems applications because of its excellent mechanical and chemical properties. However, because of its hardness, sapphire is difficult to machine. Titanium-doped sapphire is a well-known broadly tunable and short-pulse laser material and a promising broadband light source for applications in low-coherence interferometry. We investigated several methods to fabricate rib structures in sapphire that can induce channel waveguiding in Ti:sapphire planar waveguides. These methods include direct laser ablation, laser-micromachined polyimide stripes, selective reactive ion etching, and ion-beam implantation followed by chemical wet etching. Depending on the method, we fabricated channels with depths of up to 1.5 Β΅m. We will discuss and compare these methods. Reactive ion etching through laser-structured polyimide contact-masks has so far provided the best results in terms of etching speed and roughness of the etched structures
Π’ΡΠ°Π½ΡΠΏΠΎΡΡΠ½Π°Ρ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠ°: ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ ΠΈ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Ρ ΡΠ°Π·Π²ΠΈΡΠΈΡ Π² ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΌ Π΄Π΅Π»Π΅
ΠΡΠΏΡΡΠΊΠ½Π°Ρ ΠΊΠ²Π°Π»ΠΈΡΠΈΠΊΠ°ΡΠΈΠΎΠ½Π½Π°Ρ ΡΠ°Π±ΠΎΡΠ° ΠΏΠΎΡΠ²ΡΡΠ΅Π½Π° ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΡΠ°Π½ΡΠΏΠΎΡΡΠ½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠ΅ Π² ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΌ Π΄Π΅Π»Π΅. Π¦Π΅Π»ΡΡ Π΄Π°Π½Π½ΠΎΠΉ ΡΠ°Π±ΠΎΡΡ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ½ΡΠΉ Π°Π½Π°Π»ΠΈΠ· ΡΠ°ΠΊΡΠΎΡΠΎΠ², ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌΠΎΠ² ΠΈ ΠΏΡΠΎΠ±Π»Π΅ΠΌ ΡΡΠ°Π½ΡΡΠΎΡΠΌΠ°ΡΠΈΠΈ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ Π² Π³Π»ΠΎΠ±Π°Π»ΡΠ½ΠΎΠΉ ΡΠΎΡΠ³ΠΎΠ²ΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΠ΅ ΠΈ ΠΎΠ±ΠΎΡΠ½ΠΎΠ²Π°Π½ΠΈΠ΅ Π½Π°ΠΏΡΠ°Π²Π»Π΅Π½ΠΈΠΉ Π°Π΄Π°ΠΏΡΠ°ΡΠΈΠΈ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ Π ΠΎΡΡΠΈΠΈ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
Π»ΠΈΠ±Π΅ΡΠ°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΠΌΠ΅ΠΆΠ΄ΡΠ½Π°ΡΠΎΠ΄Π½ΠΎΠΉ ΡΠΎΡΠ³ΠΎΠ²Π»ΠΈ. ΠΠ°Π΄Π°ΡΠΈ: β’ΠΠΎΠ½ΡΡΠΈΠ΅, Π²ΠΈΠ΄Ρ, ΡΡΠ½ΠΊΡΠΈΠΈ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ β’ΠΠ°Π΄Π°ΡΠΈ ΡΡΠ°Π½ΡΠΏΠΎΡΡΠ½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ β’Π‘ΡΡΠ½ΠΎΡΡΡ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ β’ΠΡΠΎΠ±Π»Π΅ΠΌΡ ΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ β’ΠΠ»ΡΡΠ΅Π²ΡΠ΅ ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ β’ΠΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Ρ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ.
ΠΠ±ΡΠ΅ΠΊΡΠΎΠΌ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΏΡΠΎΡΠ΅ΡΡ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΠΈ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΡΠ°ΠΌΠΎΠΆΠ΅Π½Π½ΠΎΠΉ Π»ΠΎΠ³ΠΈΡΡΠΈΠΊΠΈ Π² Π³Π»ΠΎΠ±Π°Π»ΡΠ½ΠΎΠΉ ΡΠΎΡΠ³ΠΎΠ²ΠΎΠΉ ΡΠΈΡΡΠ΅ΠΌΠ΅.The final qualifying work is devoted to the study of transport logistics in the customs business.
The purpose of this work is a comprehensive analysis of the factors, mechanisms and problems of the transformation of customs logistics in the global trading system and the rationale for adapting the customs logistics of Russia in the context of the liberalization of international trade
Structural and electrical transport properties of superconducting Au{0.7}In{0.3} films: A random array of superconductor-normal metal-superconductor (SNS) Josephson junctions
The structural and superconducting properties of Au{0.7}In{0.3} films, grown
by interdiffusion of alternating Au and In layers, have been studied. The films
were found to consist of a uniform solid solution of Au{0.9}In{0.1}, with
excess In precipitated in the form of In-rich grains of various Au-In phases
(with distinct atomic compositions), including intermetallic compounds. As the
temperature was lowered, these individual grains became superconducting at a
particular transition temperature (Tc), determined primarily by the atomic
composition of the grain, before a fully superconducting state of zero
resistance was established. From the observed onset Tc, it was inferred that up
to three different superconducting phases could have formed in these
Au{0.7}In{0.3} films, all of which were embedded in a uniform Au{0.9}In{0.1}
matrix. Among these phases, the Tc of a particular one, 0.8 K, is higher than
any previously reported for the Au-In system. The electrical transport
properties were studied down to low temperatures. The transport results were
found to be well correlated with those of the structural studies. The present
work suggests that Au{0.7}In{0.3} can be modeled as a random array of
superconductor-normal metal-superconductor (SNS) Josephson junctions. The
effect of disorder and the nature of the superconducting transition in these
Au{0.7}In{0.3} films are discussed.Comment: 8 text pages, 10 figures in one separate PDF file, submitted to PR
Erbium ion implantation doping of opto-electronic materials operating at 1.5 mu m
Soda-lime silicate and Al/sub 2/O/sub 3/ waveguide films, LiNbO/sub 3/ single crystal, as well as crystal Si are doped with erbium by ion implantation. All materials show luminescence at 1.5 mu m, characteristic for Er, with lifetimes up to 12 m
Peter GrΓΌnberg - Nobelpreis fΓΌr Physik 2007
The year 2007 was a particularly important year for Forschungszentrum JΓΌlich and Prof. Peter GrΓΌnberg. With this book, we not only want to honour GrΓΌnberg but also to thank him for his discoveries, which he made here in JΓΌlich.
What was to become known as the giant magnetoresistance effect (GMR effect) was discovered by GrΓΌnberg in 1988 within the framework of basic research on magnetism. A read head for hard disk drives based on this discovery quickly conquered the world of industrial applications. Since 1997, the GMR effect has been used almost exclusively to read out information stored magnetically on hard drives. With more than fi ve billion read heads produced to date, statistically there is one GMR sensor for almost every
member of the human race. We use this quantum-mechanical physical effect every day in computers or hard drive recorders without even realising it. What we are aware of is the rapid development of magnetic data
storage, which is continuously opening the way for new applications. The storage capacity of hard drives has increased substantially thanks to GMR read heads and has reached 1 terabyte today. This development is set to continue. In the future, we will be using even smaller electronic devices that will be able to deal with even larger amounts of data in even shorter periods of time with a lower energy demand...
- β¦