Ultra-long-working-distance spectroscopy with 3D-printed aspherical microlenses

Researchers at the Faculty of Physics, University of Warsaw have demonstrated micrometre-sized 3D-printed aspherical microlenses which can replace bulky microscope objectives in spectroscopic measurements of single point-like light emitters (e.g. quantum dots or atomically thin 2D materials). The proposed microlenses increase the available working distance, i.e. the distance between the lens front and the sample surface, by over two orders of magnitude, and open up new perspectives for a wide class of optical experiments.