Colloidal quantum dots decorated micro-ring resonators for efficient integrated waveguides excitation

Abstract

<jats:title>Abstract</jats:title><jats:p>Micro-ring resonators made of titanium dioxide were decorated with local light sources comprising CdSe/CdS colloidal quantum dot aggregates. The active micro-resonators are operated to achieve efficient evanescent excitation of nearby co-planar integrated waveguides. Coupled-mode analysis and numerical simulations are used to capture the dynamic of the optical interaction between locally activated resonators and integrated waveguides. In this context, we exemplify the key role of resonator intrinsic loss. Next, we show that locally activated or bus-waveguide excited resonators are in optimum waveguide interaction for the same so-called critical coupling condition, although the physical origin of this property is different for each configuration. More importantly, we found that a locally activated resonator is a fabrication imperfection tolerant configuration for the coupling light of local sources into waveguides. This remarkable property originates from the opposite change of the power cycling into the resonator and the waveguide coupling efficiency as a function of the resonator-waveguide separation gap. By operating an 8-μm-radius ring resonator with loaded quality factors around <jats:italic>Q</jats:italic> = 2100, we experimentally demonstrate a 5.5-dB enhancement of the power coupled into the output waveguide compared to a direct local source waveguide excitation.</jats:p>

Integration of Colloidal Quantum Dots with Photonic Structures for Optoelectronic and Optical Devices

“…Traditional PICs are normally based on silicon technologies, but the low optical gain in these systems limit the active component applications. On the other hand, colloidal QDs are regarded as a highly promising class of gain materials for on‐chip active components such as optical amplifier [ 136 , 137 ] and coherent light source. [ 3 , 135 , 138 ] However, the on‐chip integration of the colloidal QD active components with other functional photonic devices is still a challenge due to the complexity in processing different types of materials.…”

Tailoring Electronic Properties of Colloidal Quantum Dots for Efficient Optoelectronics

“…Some of the important applications, specifically display panels, micro-resonators, micro-LEDs (μ-LEDs), solar cells, and lasers, require high-resolution and precise patterning of CQDs for higher performance and scalability. [17,19,33,[161][162][163][164][165][166][167][168] Extensive efforts have been carried out to accomplish controlled deposition and accurate patterning, and a set of such techniques can be witnessed being employed quite frequently. In this section, we summarize the key techniques known for defined patterning of CQDs, including high-resolution inkjet printing, transfer printing, direct lithography of photosensitive CQDs, and modified conventional photolithographic methods.…”

Nano antenna-assisted quantum dots emission into high-index planar waveguide

“…We consider a gold Yagi-Uda plasmonic antenna deposited onto a titanium dioxyde (TiO 2 ) planar waveguide. Yagi-Uda geometry has been chosen for efficient in plane directivity and TiO 2 material is a promissing alternative to silicon nitride for applications involving sources emitting in the visible range [27,28]. Since on chip coupling efficiency process is governed by local excitation of the nano-optical antenna, we consider few-photons sources based on CdSe/CdS QDs for characterizing and designing the on-chip plasmonic antenna platform.…”