arXiv subjects

Changyi Chen

Publications and source records attributed to Changyi Chen.

2 recordsLinked to original sources

arXiv2026

Towards on-chip nascent all-van-der-Waals polarization optical components for nanoscale photonic applications

The integration of polarization-control elements into nanoscale photonic circuits remains a central challenge for modern on-chip optical technologies, which call for continuous miniaturization. Van der Waals (vdW) crystals provide a versatile platform for the creation of such components owing to their strong optical anisotropy, high-refractive indices and atomically precise heterostructure assembly capabilities. In this work, we demonstrate an approach towards the creation of all-vdW on-chip polarization optical components, exemplified with quarter-wave plates operating in the near-infrared (NIR) spectral region, realized in specifically twisted ReSe2/alpha-MoO3 vdW heterostructures on a Si/SiO2 platform. Here, low-symmetry ReSe2 layer serves as a source of exceptionally high linearly polarized excitonic emission, whereas in-plane birefringent alpha-MoO_3 provides polarization-state conversion. Furthermore, our finite-difference time-domain (FDTD) simulations quantitatively reproduce the experimental observations with high accuracy revealing the critical roles of layer thicknesses, twist-angle, Fabry-Perot interference and emitter distribution effects in the determination of polarization conversion efficiency, which yields up to 95 % degrees of circular polarization (DoCP) for the optimized parametrization. Our findings establish a practical route towards fully integrated all-vdW polarization optical components, providing a foundation for nanoscale photonic architectures based entirely on layered materials.

physics.optics↗

arXiv2025

Two-dimensional materials as a multiproperty sensing platform

Two-dimensional (2D) materials have disrupted materials science due to the development of van der Waals technology. It enables the stacking of ultrathin layers of materials characterized by vastly different electronic structures to create man-made heterostructures and devices with rationally tailored properties, circumventing limitations of matching crystal structures, lattice constants, and geometry of constituent materials and supporting substrates. 2D materials exhibit extraordinary mechanical flexibility, strong light-matter interactions driven by their excitonic response, single photon emission from atomic centers, stable ferromagnetism in sub-nm thin films, fractional quantum Hall effect in high-quality devices, and chemoselectivity at ultrahigh surface-to-volume ratio. Consequently, van der Waals heterostructures with atomically flat interfaces demonstrate an unprecedented degree of intertwined mechanical, chemical, optoelectronic, and magnetic properties. This constitutes a foundation for multiproperty sensing, based on complex intra- and intermaterial interactions, and a robust response to external stimuli originating from the environment. Here, we review recent progress in the development of sensing applications with 2D materials, highlighting the areas where van der Waals heterostructures offer the highest sensitivity, simultaneous responses to multiple distinct externalities due to their atomic thickness in conjunction with unique material combinations, and conceptually new sensing methodology.

cond-mat.mes-hall↗