Planar photonic crystal nanocavities as functional microparticles

Planar photonic crystal nanocavities, made in a thin semiconductor membrane and suspended by breakable tethers, are released after fabrication. The cavity spectrum can be read out remotely by detecting the photoluminescence of embedded Quantum Dots. Both transfer printing and deterministic positioning of the cavities on foreign substrates by individual micromanipulation is demonstrated. The microscopic environment of the particles, including their bonding to the substrate, determines the cavities' resonance spectrum, which can be exploited in applications. As the first application, we demonstrate a novel fiber-optic sensor with a PhC cavity chiplet attached to the tip of a single-mode optical fiber.