Direct 3D-printing of microlens on single mode polarization-stable VCSEL chip for miniaturized optical spectroscopy

In this work, two-photon polymerization three-dimensional laser writing is used to integrate a microlens on the surface of single mode polarization-stable vertical-cavity surface-emitting (VCSEL) be as current-driven tunable source in compact optical guided-wave gas sensor. The conditions are optimized enable on-demand room temperature and single-step fabrication at post-mounting stage. We show that time 5 min sufficient fabricate efficiently reduces VCSEL beam divergence, without significant change its emitted power or polarization stability. lens addition spectral available range high injection currents. A two-dimensional modeling gain characteristics explain effect new transverse design proposed avoid issue.