Ultracoherent Gas Micro-Laser for Navigation and Target Recognition

Current widely-used laser technologies, based on solid-state media, suffer from low internal coherence arising from absorption within the materials of which the laser is composed. To overcome these losses, coupling the sources to large, cumbersome, and sensitive external resonators is required — assemblies comprising multiple components that compromise system stability. Furthermore, solid-state materials tend to degrade over time and lose output power due to the formation of internal defects. This study presents an alternative approach and the development of the first-of-its-kind plasma micro-laser, based on a silica resonator embedded within a plasma environment.

The development replaces the solid-state gain medium with a noble gas plasma. Since this plasma is transparent and does not chemically interact with other materials, the system exhibits inherently high coherence, a long operational lifetime free of degradation, and a structurally simple lasing cavity requiring no external resonator. This marked improvement in coherence will enable greater precision in optical measurements and will significantly enhance the performance of both defense and civilian systems — including extended-range LiDAR sensors, advanced target identification, and atmospheric transmittance measurements.

The team has successfully designed and fabricated miniature silica resonators on a silicon chip, and has constructed a modular vacuum chamber adapted for plasma generation. In the subsequent stages of the research, the resonators will be integrated into the plasma chamber for characterization of their lasing thresholds, linewidth, and environmental stability. Experiments will begin with argon gas, followed by a transition to gases such as neon, which enable lasing in spectral regions where the atmosphere is transparent and that are classified as eye-safe.