The light emission from a series of micropillar microcavities containing a fluorescent, red‐emitting conjugated polymer, is explored. Cavities are fabricated by defining two dielectric mirrors either side of a polymer active region. Focused ion‐beam (FIB) lithography is then used to etch pillar structures into the planar cavity having diameters between 1 and 11 µm. The photoluminescence (PL) emission of the cavities is characterized using real‐space tomographic and Fourier‐space imaging techniques, with emission shown to be quantized into a mode‐structure resulting from both vertical and lateral optical confinement within the pillar. The optical‐confinement effects which result in a blue‐shift of the fundamental mode as the pillar diameter is reduced is demonstrated, with a model applied to describe the energy and distribution of the confined optical modes.

Researchers from the University of Sheffield use focused‐ion beam lithography to etch micropillars into a planar microcavity formed from two dielectric mirrors placed on either side of a fluorescent conjugated‐polymer (see article number 1900067 by David G. Lidzey and co‐workers). The photoluminescence from the micropillars is explored using a series of advanced imaging techniques. It is shown that micropillar emission is quantized into a series of modes arising from vertical and lateral confinement within the pillar, with a model used to describe the energy and spatial distribution of the various optical modes.