Oblong-Shaped VCSELs with Pre-Defined Mode Patterns

VCSELs, which emit from the planar surface of the wafer rather than from the cleaved end facets, have been extensively investigated over the last years. The main advantages of these devices over the conventional edge-emitting lasers lie in their spatial and spectral output properties as well as manufacturing, testing, and packaging at lower cost. Because of their suitability for monolithic integration into two-dimensional arrays, VCSELs pave the way for a large variety of applications, such as space-parallel optical communication technologies or optical sensing and lighting using high-power sources. A new and attractive application of VCSELs in biophotonics is optical trapping, where active manipulation of biological cells [1], stacking and translation of microscopic particles [2], as well as a miniaturized system, the so-called integrated optical trap [3], were already successfully demonstrated. In order to sort particles using such an integrated optical trap, we intend to selectively deflect them from their initial flow direction with the trapping forces of a tilted, continuously emitting VCSEL array as described in [4] and the preceding article in this Annual Report. In order to create the required closely spaced intensity maxima, here we introduce a novel VCSEL which oscillates on a pre-defined high-order mode.