Breakthrough Laser Tech Enhances LiDAR Accuracy and Gas Detection

Laser technology underpins many modern applications requiring precise measurement and communication. Scientists led by NTNU's Johann Riemensberger have developed a new integrated laser that is fast, powerful, relatively inexpensive, and easy to use. The work is a collaboration with Switzerland's École Polytechnique Fédérale de Lausanne (EPFL) and chip specialist Luxtelligence. This approach overcomes key limitations of conventional precision lasers, which are typically large, costly and difficult to adjust. According to Riemensberger, such lasers could enable small, affordable, high-performance instruments and communication systems.

Advanced materials, microscopic circuits

According to the study published in Nature Photonics, the new laser is implemented on a photonic chip using advanced materials such as thin-film lithium niobate, leveraging its electro-optic (Pockels) effect for ultrafast, mode-hop-free frequency tuning. It combines the lithium niobate circuit with a commercial semiconductor gain chip, yielding a laser that is both powerful and robust.

It emits a stable beam and allows the frequency to be adjusted quickly and smoothly without mode hops. Notably, the device can be operated using a single tuning knob instead of multiple controls. Because it relies on standard chip fabrication processes, the laser can be mass-produced inexpensively. “Our findings make it possible to create small, inexpensive and user-friendly measuring instruments and communication tools with high performance,” Riemensberger says.

Self-driving cars and air quality detectors

Conventional precision lasers are often large, expensive and difficult to tune. Riemensberger notes that “our new laser solves several of these problems”. The team demonstrated the device in LiDAR (light detection and ranging) systems for self-driving cars, where lasers measure distance by timing reflected pulses. This laser achieved a range precision of about four centimeters, enabling very high-resolution environmental mapping.

Its rapid, mode-hop-free tuning allowed it to sweep across gas absorption lines, enabling sensitive detection of trace hydrogen cyanide, demonstrating potential for rapid gas sensing in safety and environmental monitoring. In fact, Simone Bianconi of EPFL notes that the laser's combination of tunable, low-noise output makes it well-suited for coherent LiDAR and precision gas sensing.