Generating and shaping terahertz vortex beams on a single chip

Terahertz waves are a promising technology for communications, imaging, and sensing due to their strong interactions with molecules and quantum materials. Harnessing such electromagnetic radiation could increase wireless communication capacity, enable new methods of high-information imaging, and even inspire new ways to probe and manipulate matter. But generating and shaping terahertz waves typically requires external optical components that are bulky, difficult to align, and sensitive to environmental disturbances.

Yan et al. designed and tested an integrated semiconductor platform that combines terahertz generation, guidance, and shaping on a single chip. The device could enable a new generation of compact, multifunctional terahertz photonic systems.

“Until now, terahertz vortex beams have typically required multiple optical components and carefully aligned experimental setups,” said author Gangyi Xu. “Our work represents a step toward putting an entire terahertz optical system onto a semiconductor chip.”

The researchers first designed a fork grating that converts part of the guided terahertz wave into a vortex beam while minimally disturbing the remaining guided wave. They then used high-resolution microfabrication techniques to build the device onto a single semiconductor chip. Lastly, they measured the spectrum, output power, polarization, and vortex properties of terahertz light generated with the device. The platform successfully created a sustained, high-purity, vortex-shaped terahertz beam.

Next, the researchers hope to integrate more functionalities, such as modulators and detectors, onto the same chip. They also envision a platform that can dynamically switch terahertz beams between vortex states or structured light forms in real time.

“In a sense, we hope to compress an entire terahertz laboratory onto a semiconductor chip,” said Xu.

Source: “Monolithically integrated electrically pumped terahertz scalar vortex lasers,” by Chuanfeng Yan, Kai Wang, Cheng Tan, Lianghua Gan, Yueheng Zhang, Yulong Fang, and Gangyi Xu, Applied Physics Letters (2026). The article can be accessed at https://doi.org/10.1063/5.0336306 .