Tunable Ring Laser Chips Broaden Mid-Infrared Wavelength Control

Tunable semiconductor lasers are vital for applications ranging from high-speed telecommunications to gas sensing and medical diagnostics, but existing devices face trade-offs in tuning range, accuracy, and complexity. Theodore P. Letsou, Johannes Fuchsberger, and colleagues have now demonstrated a monolithic mid-infrared ring-array laser chip that provides smooth, wide-range tuning without moving parts by integrating multiple ring resonators of varied sizes onto a single waveguide-based platform. Published in Optica, their hybrid quantum-cascade ring laser generates single-mode emission at selectable wavelengths within the 8 µm band, offering robust unidirectional operation, facile fabrication, and scalable performance. This compact tunable laser chip could pave the way for versatile, cost-effective systems in sensing, spectroscopy, and beyond.

See the publication here in Optica and the press release from Harvard SEAS.

Image credit: Joshua Mornhinweg