Pumplaser fuer optische Faserverstaerker Schlussbericht

RW pumplasers for Er"3"+-doped fibre amplifiers have been realized with an emission wavelength of 980 nm, which based on MOVPE-grown pseudomorphic InGaAs-QW GaAs/AlGaAs-SCH. With DC driving currents I=210 mA an emission power P#>=#150 mW in the fundamental mode has been achieved at facet coated and soldered chips. In pulse regime up to I=1 A a power >700 mW has been measured. The internal optical losses of the laser chip were lowered to #alpha#_i#<=#3 cm"-"1. This enabled the enhancement of the external efficiency up to 0,9 mW/mA. To reduce the veritical far-field angle special LOC structures have been developed with an InGaAs-DQW as active layer. The far-field angle was below 35 . Investigations of the long-term behaviour demonstrated degradation rates #beta#<5 x 10"-"5/h at 40 C and emission powers of 90 mW. The best value was 3 x 10"-"6/h at 70 mW over 3000 h. The analysis of nonradiative currents provided hints to a screening with respect to facet erosions. (orig.)Available from TIB Hannover: F97B154+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Förderschwerpunkt NOVALAS : Grundlegende Untersuchungen zur Technologie von Hochleistungsdiodenlasern, Teilvorhaben: Hochleistungsdiodenlaser auf der Basis von Al-freien Quantengräben und Wellenleitern im Wellenlängenbereich 800 - 1000 nm ; Schlussbericht

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High-energy electron beam lithography of octadecylphosphonic acid monolayers on aluminum

Monolayers of octadecylphosphonic acid were self-assembled on silicon substrates sputter coated with aluminum. Patterning of the self-assembled monolayer was achieved by high-energy electron (50 kV) illumination using an electron beam lithography tool. The change in chemical composition of the exposed monolayer was investigated by time-of-flight secondary ion mass spectrometry over an area of 100 x 100 mu m(2). The electron dose required to fully expose the SAM was found to be about 6 mC/cm(2). Gratings were exposed with line widths from 10 mu m to 100 nm. The resulting patterns were imaged using friction force microscopy. It was found that the minimum line width is limited to ca. 100 nm by the patterning resolution. The pattern resolution achieved, ca. 40 nm, is equal to the grain size of the sputter-coated aluminum layer, and the possibility that the grain size limits the pattern resolution is discusse