High-frequency radiation in the terahertz (THz) band—sitting between infrared light and microwaves—has long tempted engineers with capabilities such as ultrafast wireless links, advanced security screening, remote sensing, and medical imaging. Yet turning that promise into practical hardware remains difficult. Most THz systems today are still constrained by their size, complexity, and limited scalability.
A growing alternative has been photonics-based THz technology, which uses light to generate and process THz signals with excellent bandwidth and power efficiency. In principle, photonic approaches can deliver the high data rates required by next-generation communication and sensing platforms. In practice, however, current optoelectronic THz setups typically depend on multiple separate components—lasers, amplifiers, modulators, sources, and detectors—that must be individually built and meticulously aligned.
A UCLA-led team reports a strategy to collapse those functions onto a single semiconductor chip that is compatible with modern photonic integrated-circuit manufacturing. Published in Nature Communications, the work aims to move THz optoelectronics from laboratory demonstrations toward compact, mass-producible devices.
The core idea is to adapt THz generation and detection for integration with photonic integrated circuits. Rather than relying on bulky, off-chip architectures, the researchers use quantum well semiconductor structures—thin, engineered layers already common in photonic platforms—to enable multiple THz operations on the same substrate.
Their key innovation is gain-enhanced interband photomixing. Two laser beams interfere within the quantum well structure in a way that produces THz signals at the target frequency, while simultaneously supporting detection. This “photomixing” route leverages optical control to translate light-beam combinations into THz waveforms.
Experiments show that, compared with conventional photomixer-based THz approaches, their quantum-well implementation achieves highly efficient THz generation and sensitive THz detection. The results suggest that integrated quantum well gain can strengthen both the signal creation and the readout process.
Beyond performance, the technical pathway matters: the team demonstrates that THz functions can be realized on a chip using industry-standard fabrication concepts familiar to photonics engineers. That compatibility could reduce cost, improve repeatability, and ease scaling.
“Terahertz optoelectronic systems have been bulky, expensive, power-hungry and difficult to scale,” said Mona Jarrahi. By demonstrating many functions on one chip, the study positions THz photonics for real-world communication, imaging, and sensing applications.
In addition to Jarrahi, UCLA doctoral students Yifan Zhao, Shahid-E-Zumrat, and Szu-An Tsao contributed to the work from Jarrahi’s Terahertz Electronics Lab. Funding came from the U.S. Office of Naval Research, the U.S. Department of Energy, and the Institution of Engineering and Technology Harvey Prize.
Keywords
Terahertz; Photonics; Quantum wells; Photomixing; Integrated circuits; Signal processing; Semiconductors; Diodes; Electronics; Optical gain
Article Title: Terahertz generation and detection through gain-enhanced interband photomixing in quantum well structures
News Publication Date: 13-May-2026
Web References: https://doi.org/10.1038/s41467-026-73080-6
References: 10.1038/s41467-026-73080-6
Image Credits: Terahertz Electronics Lab/UCLA
