MBE growth and characterization of multilayer structures for vertically emitting laser devices
FacultiesFakultät für Ingenieurwissenschaften und Informatik
LicenseStandard (Fassung vom 01.10.2008)
This work concerns molecular beam epitaxy (MBE) growth and characterization of multilayer structures for vertically emitting laser devices. In particular, this thesis is focused on the fabrication of novel VCSEL (vertical-cavity surface-emitting laser) and VECSEL (vertical-external-cavity surface-emitting laser) multilayer structures grown on GaAs substrate. Several VCSEL structures for emitting wavelengths of 760, 850, and 980 nm were realized and the corresponding devices show high performance and have direct technological applications. As example, single-mode 760 nm VCSELs are successfully employed in oxygen sensing, or integrated VCSELs-photodetector systems allow bidirectional data transmission in full-duplex mode at 2.5 Gbit/s over 50 m graded-index multimode fiber. As far as regard VECSELs, samples for devices having emitting wavelengths of 850 nm and 980 nm were produced. High-performance 850 nm quantum-well-pumped VECSELs having a slope efficiency of 67 % were demonstrated. The calibration techniques of the MBE system are described and applied to the practical cases of the growth of complex laser structures. Therefore, an important part of this work is devoted to HRXRD (high-resolution x-ray diffraction) analysis of the grown samples. This is a powerful tool to characterize not only the strain configuration and the compositional profile of the layers, but also to indirectly monitor the molecular fluxes improving the reliability of the MBE system.
Subject HeadingsMolekularstrahlepitaxie [GND]
Semiconductor lasers [LCSH]
X-rays. Characterization [LCSH]