An Optical-Fiber-Based Airborne Particle Sensor

A new optical-fiber-based airborne particle counter is reported. Unlike traditional light-scatter-based techniques, the particle is detected through the drop in optical fiber coupling efficiency as the particle disrupts the electromagnetic mode of the optical beam. The system is simple, substantially smaller than traditional systems, and does not require high power laser input. This makes it attractive for wearable air quality monitors where size is a premium. There is close agreement between theoretical model and experimental results for solid and liquid particles in the 1 to 10 µm range.