Phototunable chip-scale topological photonics: 160 Gbps waveguide and demultiplexer for THz 6G communication

Abstract

The revolutionary 5G cellular systems represent a breakthrough in the communication network design to provide a single platform for enabling enhanced broadband communications, virtual reality, autonomous driving, and the internet of everything. However, the ongoing massive deployment of 5G networks has unveiled inherent limitations that have stimulated the demand for innovative technologies with a vision toward 6G communications. Terahertz (0.1-10 THz) technology has been identified as a critical enabler for 6G communications with the prospect of massive capacity and connectivity. Nonetheless, existing terahertz on-chip communication devices suffer from crosstalk, scattering losses, limited data speed, and insufficient tunability. Here, we demonstrate a new class of phototunable, on-chip topological terahertz devices consisting of a broadband single-channel 160 Gbit/s communication link and a silicon Valley Photonic Crystal based demultiplexer. The optically controllable demultiplexing of two different carriers modulated signals without crosstalk is enabled by the topological protection and a critically coupled highquality (Q) cavity. As a proof of concept, we demultiplexed high spectral efficiency 40 Gbit/s signals and demonstrated real-time streaming of uncompressed high-definition (HD) video (1.5 Gbit/s) using the topological photonic chip. Phototunable silicon topological photonics will augment complementary metal oxide semiconductor (CMOS) compatible terahertz technologies, vital for accelerating the development of futuristic 6G and 7G communication era driving the real-time terabits per second wireless connectivity for network sensing, holographic communication, and cognitive internet of everything.The symbiosis of physical, digital, and biological worlds is one of the core visions of sixth-generation (6G) communication 1 , driven by various foreseen disruptive applications like industrial automation, innovative society, intelligent healthcare system, massive internet-ofeverything, and energy-efficient networks. The realization of these applications critically requires ultra-high-speed connectivity with submillisecond latency times 2,3 . One of the tenets of the development of 6G technology is to expand the frontier of the radiofrequency (RF) spectrum into the terahertz (THz) band (beyond 300 GHz) for accessing the larger bandwidth 2,4 . As 6G wireless networks evolve, emerging communication devices are expected to handle a large volume of data, such as the real-time transmission of high resolution 8K video, paving the path towards remote healthcare and human augmentation. Thus, the system-on-chip architecture must support significant bandwidth signals to efficiently process and compute the extensive volume data to integrate seamlessly with 6G networks. High-speed on-chip

Lightweight MXene-Based Hybrid Aerogels with Ultrabroadband Terahertz Absorption and Anisotropic Strain Sensitivity

“…For example, the combination of strain-sensing and THz absorption can greatly reduce the undesirable radiation of THz antennas, and simultaneously monitor the strain borne by them to prevent damage caused by excessive load . Device packing materials also require both THz absorption and strain-sensing performance. , …”

“…10 Device packing materials also require both THz absorption and strain-sensing performance. 2,11 In fact, macroporous three-dimensional (3D) network structures offer a unique route to achieve high-performance electromagnetic wave or light absorption in lightweight composite materials, e.g., foam and aerogel. 10−13 Their advantages mainly manifest from two aspects: (1) improved impedance matching arising from high porosity that allows more incident waves to enter and (2) enhanced energy dissipation caused by multiple scattering inside pores and induced currents on the pore wall by the entered wave.…”

“…The fast development of Terahertz (THz) technology in a vast variety of intriguing fields, including sixth generation (6G) wireless communication, , laser systems, , medical imaging, and biological detection, , brings in the strategical problem of THz wave radiation. Featured with high signal-carrier frequencies and nonionizing photon energy, such radiation poses unusual threats to electronic devices, human health, and even military safety. − Lightweight, broadband, and high-efficient THz wave absorbers, though still remain challenging by the limits of intrinsic material properties, are thus highly in demand to suppress THz radiation by dissipating its energy.…”

All-Dielectric Tunable Terahertz Metagrating for Diffraction Control

“…However, many functional devices are inadequate in this frequency range . Ranjan Singh and colleagues offers new opportunities to create terahertz waveguides and metasurfaces for 6G communication with robust topological and real-time transmission. − The metagratings, as a kind of important metasurface, mostly work in the infrared and visible wavelengths. It is rarely reported in the 6G communication window from 0.1 to 0.3 THz.…”

Spin-decoupled excitation and wavefront shaping of structured surface waves via on-chip terahertz metasurfaces

“…By carefully designing the shapes and sizes of meta-atoms, plenty of EM wave manipulating applications have been achieved, including modulators, 9,10 holography, 11,12 polarization control, 13,14,28 vectorial fields, 15,16 wavefront manipulation, 17,18,[38][39][40][41] edge detection, [30][31][32] and topological photonics. [21][22][23][34][35][36] However, to date plentiful metasurfaces concentrate on the manipulation of PWs, while the manipulation of SWs through metasurfaces is not common. There is some research about the excitation and manipulation methods of SWs, including the helicity-dependent directional coupling of SWs, 44,45 spin-momentum locking excitation of edge waves 49 and spoof surface plasmon polaritons, 50 and deflection or focusing of SWs.…”