Fabrication of integration-capable surface-relief VCSEL arrays for miniaturized optical manipulation of microparticles

Recently, optical manipulation combined with microfluidics has gained increasing interest in the field of biological sciences. This combination enables fast and inexpensive sample analysis and manipulation with reduced consumption of analytes. Another important factor in biology and medicine is the contamination-free handling of micrometer sized biological cells that makes the combination an attractive tool for the researchers. In recent years, the use of VCSELs (vertical-cavity surface-emitting lasers) as light sources in optical manipulation has got significant attention for their various advantages like the possibility of two-dimensional VCSEL array formation and their integration capability that enable parallel particle manipulation and miniaturization, respectively. In this paper, we present the fabrication of the integration-capable VCSEL arrays to form a VCSEL-based miniaturized optical trap module. To enhance the suitability of the VCSELs for optical trapping, we fabricate AlGaAs-GaAs-based surface-relief VCSEL arrays with a very small device pitch.