Modification and Resonance Tuning of Optical Microcavities by Atomic Layer Deposition

Abstract

Recently, enormous interest has been focused on the nanofabrication of optical micro-and nanocavities for applications in labon-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.

Integrative optofluidic microcavity with tubular channels and coupled waveguides via two-photon polymerization

“…Though the microcavity is tested hydrophobic to water, water-based solution sensing can also be realized after a simple surface modification process. 19,43,44 For example, a thin layer coating of metal oxides (like several nanometers Al 2 O 3 or TiO 2 ) by atomic layer deposition can dramatically enhance the inner surface hydrophilic ability and water wettability. 43,44 In addition, this mild modification process has little influence on the size and performance of the tubular microcavity.…”

Observation of higher order radial modes in atomic layer deposition reinforced rolled-up microtube ring resonators

“…Concurrently, ALD coatings modify the spectral position of resonances and influence their quality-factor (Q-factor) [16][17][18]. Earlier, investigations focused on comparatively thin coatings and observed broad optical modes [16], which are inferior for sensing applications.…”

Wide Bandgap Perovskite Photovoltaic Cells for Stray Light Recycling in a System Emitting Broadband Polarized Light

“…The polarization extinction ratio as well as the transmitted p-pol light power achieved in the current h-CPP design, could be increased by the use of more uniform deposition methods such as atomic layer deposition or high-power pulsed magnetron sputtering. [36,37] In such scenario, the optimized polarizing structure applied for display illumination could reach a polarized light emission larger than 37% of the total incident light, [24] while the presented WBG perovskite PV cells would recycle the stray light with an average efficiency over 34%. Therefore, the combination of these elements could reduce the power losses relative to devices that incorporate absorbing polarizers by about 20%, as detailed in Section S4 in the Supporting Information.…”