Abstract

Sessile microdroplets of water and other polar liquids take almost spherical shapes when standing on a superhydrophobic surface. With their truncated microsphere geometry, they act as optical microcavities hosting whispering gallery modes. We achieved coupling to liquid droplet resonators kept in a controlled humidity chamber with optical fiber waveguides. In these experiments, quality factors exceeding 1 million were observed. A method for self-stabilization of the size of the droplet resonators was also demonstrated using a fixed wavelength heating laser in addition to the probe laser coupled to the same tapered optical fiber. Self-stabilization mechanism relied on the absorption resonances of the heating laser encountered by an initially condensating droplet.

© 2017 Optical Society of America