All-optical airflow sensor enables simultaneous speed and direction measurement

Area of Science:

• Optoelectronics
• Fluid Dynamics
• Sensor Technology

Background:

• Accurate measurement of airflow speed and direction is crucial in various scientific and engineering fields.
• Existing airflow sensors may have limitations in terms of accuracy, omnidirectionality, or measurement principles.

Purpose of the Study:

• To propose and demonstrate a new all-optical airflow sensor capable of simultaneous measurement of airflow speed and direction.
• To achieve high-accuracy, omnidirectional airflow measurement using an optical triangulation concept.

Main Methods:

• The sensor utilizes a suspending tapered fiber tip as the flow interaction element and a multicore fiber as the localization reference.
• Detection light from the tapered fiber is coupled into the multicore fiber. Airflow induces deflection in the fiber tip, altering optical power distribution among the multicore fibers.
• The changes in optical power within the three triangularly arranged cores correlate with airflow speed and direction.

Main Results:

• The all-optical sensor successfully measured omnidirectional airflow with speeds up to 90 mm/s.
• Experimental results demonstrated high fidelity in capturing both airflow speed and direction.
• The sensor's performance is dependent on structural parameters like core spacing and fiber dimensions.

Conclusions:

• The proposed all-optical sensor offers a promising solution for accurate, simultaneous measurement of airflow speed and direction.
• The triangulation-based optical principle enables robust and sensitive airflow detection.
• Further optimization of structural parameters can enhance the sensor's performance range and accuracy.