A photonic integrated chip platform for interlayer exciton valley routing

Abstract

Interlayer excitons in two-dimensional semiconductor heterostructures show suppressed electron–hole overlap resulting in longer radiative lifetimes as compared to intralayer excitons. Such tightly bound interlayer excitons are relevant for important optoelectronic applications, including light storage and quantum communication. Their optical accessibility is, however, limited due to their out-of-plane transition dipole moment. In this work, we design a complementary metal–oxide–semiconductor-compatible photonic integrated chip platform for enhanced near-field coupling of these interlayer excitons with the whispering gallery modes of a microresonator, exploiting the high confinement of light in a small modal volume and high-quality factor of the system. Our platform allows for highly selective emission routing via engineering an asymmetric light transmission that facilitates efficient readout and channeling of the excitonic valley state from such systems.

Emission Engineering in Monolithically Integrated Silicon Nitride Microring Resonators

“…We have performed FDE simulations to optimize the bent waveguide cross-section dimension (height and width, h × w) by plotting the effective index versus dimensions (h, w). 40 The bending radius R also plays a pivotal role in cavity mode propagation losses. A 30-μm-diameter SiN-microring resonator was taken into account with an optimal bending loss of the propagating cavity-coupled emitter mode.…”

“…Engineered optical microcavities have attracted enormous attention to enhance light–matter interactions and have opened opportunities for in-depth fundamental research and potential applications in the wide area of photonics and optoelectronics. Various configurations based on distinct photonic mode confinement physics of optical microcavities have been explored. ,− One popular class of cavities among them is the whispering gallery mode (WGM) type microcavity, which has shown high performance and on-chip integration compatibility. ,,− WGM microcavities offer a high Q factor and electromagnetic field localization in a small mode volume. In the field of silicon photonics, the microring-like stable planar structure (crucial for semiconductor processing) is a commonly employed WGM-type microcavity.…”

“…In the field of silicon photonics, the microring-like stable planar structure (crucial for semiconductor processing) is a commonly employed WGM-type microcavity. Notably, efficient coupling-out of these trapped WGM cavity modes for out-of-plane or off-chip collection has encountered key challenges, , unlike in-plane coupling scenarios (on-chip collection). ,,− Although several nanophotonic microcavity architectures have been investigated to obtain WGMs spectrum in off-chip collection schemes, for example, III–V microcavity structures , and 2D materials, they either employ nonplanar geometries, require hybrid and complex integration or are not compatible with CMOS fabrication technology. Although extensive examination has been conducted on the photoluminescence (PL) in the context of SiN films and waveguides, − ,− the exploration of the resonant modes of SiN microcavity, specifically the detection of whispering gallery modes (WGMs), through the excitation and coupling of a quantum light source embedded in SiN material, has not been investigated to the best of our knowledge.…”

“…We have performed FDE simulations to optimize the bent waveguide cross-section dimension (height and width, h × w ) by plotting the effective index versus dimensions ( h , w ) . The bending radius R also plays a pivotal role in cavity mode propagation losses.…”