Spectroscopic detection of radiocarbon dioxide based on optical feedback linear cavity enhanced absorption spectroscopy

Spectroscopic detection of radiocarbon dioxide ((CO2)-C-14) offers several advantages, including real-time detection, on-site measurement capability, and ease of operation. Here, we propose a novel (CO2)-C-14 detection technique that utilizes optical feedback linear cavity enhanced absorption spectroscopy. The feedback phase is actively compensated by adjusting the light path length. The combination of cavity-based technique and optical feedback enables the recording of stable and enhanced (CO2)-C-14 spectra. Through Allan deviation analysis, a minimal detectable (CO2)-C-14 concentration of 3.5 parts-per-trillion is achieved. This technique has the potential to contribute to the monitoring of the radiocarbon emissions in the air of nuclear power plants.