BACKGROUND Because specific marker molecules for phenotypical identification of mesenchymal stem and progenitor cells are missing, the assessment of the in vitro-differentiation capacity is a prerequisite to characterize these cells. However, classical differentiation protocols are often cell-consuming and time intensive. Therefore, the establishment of… (More)
Small-signal analysis and polarization stability performance of single-mode VCSELs for MEMS atomic clock applications " , in Proc.  A. Gadallah and R. Michalzik, " Densely-packed 2-D matrix-addressable vertical-cavity surface-emitting laser arrays " , in Proc. High-power single-higher-order-mode VCSELs for optical particle manipulation " , in… (More)
We report fabrication and characterization of a novel type of vertical-cavity surface-emitting laser (VCSEL). A dotted surface etch in an oblong-shaped output aperture is utilized to select a certain higher-order transverse mode. Optical trapping and particle manipulation are attractive applications for these VCSELs.
We report high-power single-higher-order transverse mode emission of a large-area oxide-confined rectangular-shaped VCSEL with a multi-spot shallow surface relief. Both a record-high output power of 12 mW and a record-low differential series resistance of 18 ohms are achieved. Stable single-higher-order transverse mode emission with a side-mode suppression… (More)
We report on fabrication and characterization of densely packed top-emitting 16 × 16 elements wire-bonded matrix-addressable vertical-cavity surface-emitting laser (VCSEL) arrays , which may find future applications such as non-mechanical particle movement with optical multi-tweezers, confocal microscopy or free-space communications with beam steering… (More)
We report on the theoretical analysis of a novel type of vertical-cavity surface-emitting laser (VCSEL) that provides selection of a certain higher-order transverse mode. This selection is based on a spatial variation of the threshold gain by adding an antiphase layer with an etched relief structure. The field intensity profile emitted from this laser is… (More)