Integrated optical gas sensing and wireless communication in the mid-infrared

This study demonstrates the feasibility of a hybrid open-path optical communication and gas sensing system utilizing an 8 µm quantum-cascade laser (QCL). The system integrates hydrogen sulfide (H₂S) detection with wireless optical communication, enabling real-time monitoring over large distances with minimal infrastructure. Spectral simulations based on HITRAN2020 were used to select an optimal wavelength (1234.6 cm⁻¹) that ensures minimal interference from atmospheric H₂O and CO₂ while maintaining high sensitivity for H₂S. Experimental validation confirmed the system’s independent capabilities for sensing and communication. Under simultaneous operation, the system demonstrated robust performance with an inverse relationship between bit error rate (BER) and gas sensing accuracy as H₂S concentration varied. The intersection point of these performance metrics (∼8% H₂S) highlights the system’s operational feasibility at relevant leak concentrations in oil and gas environments. This work lays the groundwork for advanced hybrid systems applicable to industrial safety and environmental monitoring.