Transient thermoreflectance imaging of active photonic crystals

Abstract

Transient thermoreflectance imaging is used to study the dynamics of the temperature inside active two-dimensional photonic crystals (PhCs). We developed a pump-probe setup suited for optically pumped devices that presents submicrosecond time resolution and submicrometer spatial resolution. Characteristic thermal dissipation times of 429 ns in a PhC Bloch mode cavity and of 999 ns in a PhC membrane are measured. This technique gives also access to the diffusivity of the suspended PhC. © 2010 American Institute of Physics.