Reviewed by Lexie CornerApr 15 2025
Researchers at New York University Abu Dhabi (NYUAD), led by Professor Mahmoud Rasras and Dr. Ghada Dushaq, have developed a novel solution to improve non-reciprocal optical response. They achieved this by integrating multilayer CuCrP₂S₆ (CCPS), a two-dimensional multiferroic material, onto silicon microring resonators (MRRs), resulting in a compact and efficient device.
Non-Reciprocal Photonic Response in CCPS-Integrated Silicon Resonators. a, Schematic of the CCPS/Si microring resonator under an applied magnetic field, showing CW and CCW light propagation differences. b, Electric field intensity profiles for TE modes at 1550 nm for bare and CCPS-integrated waveguides. c, TEM cross-section of CCPS-integrated waveguide. d, Experimental transmission spectra illustrating non-reciprocal resonance wavelength splitting. Image Credit: Dushaq, G., Serunjogi, S. et al.
Non-reciprocal optical devices are crucial for quantum computing, optical signal processing, and telecommunications because they violate Lorentz reciprocity. Traditional magneto-optic systems, which rely on large garnet materials, are difficult to integrate with silicon photonics due to their size and incompatibility.
The CCPS material’s intralayer ferromagnetic ordering and easy-plane magnetocrystalline anisotropy create an asymmetry in propagation between clockwise (CW) and counterclockwise (CCW) directions when a magnetic field is applied to the CCPS-integrated silicon resonator.
The team’s device demonstrates significantly low insertion loss (0.15–1.8 dB), strong isolation (28 dB at 1550 nm), and resonance splitting of 0.4 nm, corresponding to a 50 GHz bandwidth. By operating directly in the transverse electric (TE) mode, the design simplifies integration by eliminating the need for extra polarization rotators.
The hybrid CCPS/Si device, with a small size (22 µm–55 µm interaction length and 39 nm–62 nm flake thickness), outperforms conventional non-reciprocal platforms in terms of size and optical losses. Its enhanced performance makes it suitable for practical applications in next-generation optical isolators, modulators, and advanced photonic circuits, offering low insertion losses and excellent isolation.
Our research represents a significant step toward compact, efficient non-reciprocal devices by leveraging the unique properties of 2D multiferroic materials.
Dr. Ghada Dushaq, Study Lead, New York University Abu Dhabi
Future research will focus on improving material integration, reducing device footprints, and increasing operating bandwidth, enabling the development of new photonic architectures and applications in optical communications and computation.
Journal Reference:
Dushaq, G., et al. (2025) Non-reciprocal response in silicon photonic resonators integrated with 2D CuCrP2S6 at short-wave infrared. Light: Science & Applications volume. doi:10.1038/s41377-025-01826-w.