A Frequency-Detection-Type Photoelectric Anemometer

This article reports a novel photoelectric anemometer based on a gallium nitride (GaN) optoelectronic integrated chip. The emitter and detector components of the optoelectronic chip are monolithically integrated through wafer-scale microfabrication techniques on a GaN-on-sapphire substrate. Following microfabrication, the chip is encased within a rectangular cavity and coupled with a single-ended fixed-supported flexible film attached to one side of the enclosure, thus forming the photoelectric anemometer. Practical testing within a wind tunnel confirms the efficacy of the sensor. The results demonstrate that the integration of the multiquantum wells (MQWs) light-emitting diode (LED) and photodetector (PD) enables precise detection of flexible film vibration frequency under diverse airflow conditions, facilitating wind speed measurement within the range of 2.4–27.0 m/s. This method of wind speed measurement exhibits excellent output linearity, notable repeatability and stability. The attractive features of the proposed device, including compactness, small size, and broad linear measuring range, open up new possibilities for extending the wide applications of wind detection based on GaN photoelectric devices.