Whispering gallery resonances in semiconductor micropillars

Abstract

In this letter, the authors observe high quality (Q up to 20 000) whispering gallery modes (WGMs) with small modal volumes V∼0.3μm3 in 4–5μm Al(Ga)As∕GaAs micropillars by employing an experimental geometry in which both excitation and collection of emission are in a direction normal to the sidewalls of the pillars. They show that WGMs provide at least two times larger values of the figure of merit for strong coupling applications Q∕V compared to “photonic dot” states in pillars with comparable size.