A Review on Terahertz Technologies Accelerated by Silicon Photonics

Abstract

In the last couple of decades, terahertz (THz) technologies, which lie in the frequency gap between the infrared and microwaves, have been greatly enhanced and investigated due to possible opportunities in a plethora of THz applications, such as imaging, security, and wireless communications. Photonics has led the way to the generation, modulation, and detection of THz waves such as the photomixing technique. In tandem with these investigations, researchers have been exploring ways to use silicon photonics technologies for THz applications to leverage the cost-effective large-scale fabrication and integration opportunities that it would enable. Although silicon photonics has enabled the implementation of a large number of optical components for practical use, for THz integrated systems, we still face several challenges associated with high-quality hybrid silicon lasers, conversion efficiency, device integration, and fabrication. This paper provides an overview of recent progress in THz technologies based on silicon photonics or hybrid silicon photonics, including THz generation, detection, phase modulation, intensity modulation, and passive components. As silicon-based electronic and photonic circuits are further approaching THz frequencies, one single chip with electronics, photonics, and THz functions seems inevitable, resulting in the ultimate dream of a THz electronic–photonic integrated circuit.

A Tutorial on Mathematical Modeling of 5G/6G Millimeter Wave and Terahertz Cellular Systems

“…For example, generators, mixers, amplifiers, etc. all need to work at much higher frequencies and THz electronics may even be based on principally new materials, see, e.g., [112], [113]. The same applies to signal processing techniques that needs to be utilized to form the waveforms over channels with much higher bandwidths [114], [115].…”

Sub-terahertz silicon-based on-chip absorption spectroscopy using thin-film model for biological applications

“…In this paper, a silicon-based chip is proposed to characterize biomolecules in the sub-THz range of frequencies. Waveguides made of high-resistivity silicon (HR-Si) incurs lower insertion loss, and as a result, waveguide length can be extended to achieve better wave-mater interaction 15 – 20 . In contrast to a photonic crystal waveguide in which guiding channel is supported by in-plane band-gap structures, all sides of the proposed suspended silicon waveguide are accessible and surrounded by air.…”

Surface Oxygen Interfacial Diffusion Suppression for Enhanced Spintronic Terahertz Radiation Emission

“…Various silicon-based components, such as transmitters, − antennas, ,− waveguides, ,, modulators, and communication links have been demonstrated for THz wireless communication applications. Therefore, it would prove advantageous to develop a compact and efficient source of THz radiation that is compatible with and easily integrable onto Si platforms …”

“…Therefore, it would prove advantageous to develop a compact and efficient source of THz radiation that is compatible with and easily integrable onto Si platforms. 23 Silicon substrate-based spintronic THz emitters can easily be fabricated by physical thin-film deposition processes. Silicon substrates, however, are known to contain oxygen impurities, and if exposed to the atmosphere, a native oxide layer grows on the order of a nanometer in thickness.…”