Modification and Resonance Tuning of Optical Microcavities by Atomic Layer Deposition†

Recently, enormous interest has been focused on the nanofabrication of optical micro- and nanocavities for applications in lab-on-a-chip and quantum optics. At the same time, the atomic layer deposition (ALD) process presents several advantages for the fabrication and modification of micro- and nanostructures because of its atomic level thickness fine-tuning and perfect coating conformability in three-dimensional (3D) structures. Hence, ALD technology has been directed into the field of optical microcavities for the tracking and tuning of their properties. In this short review, we will summarize recent progress in the application of ALD on optical microcavities. Firstly, we will briefly introduce ALD technology and emphasize its distinctive features when applied to optical microcavities. Then, various microcavities such as photonic crystals, opals, and tubular microcavities will be illustrated to demonstrate their development with the assistance of ALD technology. Such an influential manufacturing tool for optical devices could inspire numerous interesting applications, as concluded in the final part.