A miniaturized VCSEL-based system for optical sensing in a microfluidic channel

We report on design and fabrication of a VCSEL-based Micro-Optical-Electrical-Mechanical-System (MOEMS) suited for portable optical biosensors. It is based on a tunable polymer microlens directly integrated on the surface of the VCSEL laser device. We demonstrate that this method leads to a VCSEL focusing at a working distance of ~300μm suitable for optical analysis in a microfluidic channel. Moreover, as the microlens can be vertically moved up to 8μm with an applied power of only 43 mW (3V), a dynamic scan of the laser spot is possible over 100μm. This integrated approach opens new insights for the use of VCSEL arrays in miniaturized optical sensors.