UCLA researchers have demonstrated a practical method to integrate terahertz wave generation and detection onto a single semiconductor chip using industry-standard fabrication techniques, opening the door to faster wireless communication, portable imaging devices, and compact chemical sensors that could eventually move terahertz systems from bulky laboratory equipment to manufacturable chips.
Terahertz radiation occupies the electromagnetic spectrum between microwaves and infrared light, roughly 0.1 to 10 terahertz. Researchers have long recognized its potential for high-bandwidth communication, security scanning, and scientific sensing, but practical systems have remained largely confined to lab benches because generating and detecting terahertz signals reliably required specialized equipment and exotic materials.
The UCLA team’s approach, which they call the Monolithically Integrated Terahertz Optoelectronics (MITO) platform, integrates sources, detectors, amplifiers, and modulators on a shared semiconductor substrate. The key components are quantum-well PIN photodiodes made from gallium arsenide and aluminum gallium arsenide (GaAs/AlGaAs), materials already widely used in commercial photonic integrated circuits.
The device works by directing two laser beams with slightly different frequencies into the quantum well structure. The overlap creates an electrical oscillation equal to the frequency difference between the two beams. When that difference falls in the terahertz range, a terahertz signal is produced. The same structure can operate in reverse to detect incoming terahertz waves with high sensitivity.
In prototype tests, the MITO platform demonstrated frequency-tunable terahertz generation and detection across the 100 to 500 gigahertz range, the lower end of the terahertz band. Critically, the team integrated a semiconductor optical amplifier on the same chip that boosted generation efficiency approximately tenfold while reducing the required optical power.
A previous assumption in the field held that electrons trapped in quantum wells would escape too slowly to support terahertz-frequency operation. The UCLA team’s measurements showed electrons escape in less than one trillionth of a second, fast enough for the terahertz regime.
“By demonstrating that many of these functions can be integrated onto a single chip using proven industry-standard fabrication platforms, our study opens the door to practical, scalable terahertz technologies for real-world applications,” said Mona Jarrahi, professor of engineering at UCLA and lead researcher on the project.
The current prototype still relies on external lasers, but the platform is designed to eventually accommodate on-chip tunable lasers and additional photonic components. The team’s next steps include integrating more components, improving performance, and scaling to larger arrays of terahertz sources and detectors.
The research was published in Nature Communications.
Sources: A chip that creates and senses terahertz waves could shrink future networks (Interesting Engineering, July 2026); Nature Communications