基于Fabry-Perot干涉仪的微型光纤风速仪

Miniature optical fiber anemometer based on Fabry-Perot interferometer

提出了一种由硅片和单模光纤(SMF)端面组成的法布里—珀罗(Fabry-Perot)干涉仪型风速计。风速计利用硅优越的热学和光学特性,当红外信号通过硅Fabry-Perot干涉仪时,可以通过红色二极管激光器注入的光束对硅Fabry-Perot干涉仪进行加热,而不会受到加热光的任何干扰。当传感器置于较强气流(风)中时,硅片热损失的增加,将会引起Fabry-Perot干涉仪光程的减小,从而导致输出光谱蓝移,风速越高,波长偏移越大。通过调节加热功率,可以改变风速计的响应范围和灵敏度。实验结果表明:在风速为4 m/s时,观察到波长偏移为-0.574 nm。当施加更大的加热功率时,预期会有更好的灵敏度。该传感器具有结构简单、成本低、响应快等特点。

A Fabry-Perot interferometer type anemometer composed of silicon wafers and single mode fiber(SMF)end faces is proposed.The anemometer utilizes the superior thermal and optical properties of silicon.When the infrared signal passes through the silicon Fabry-Perot interferometer,the silicon Fabry-Perot interferometer can be heated by the injected beam of the red diode laser without any interference from the heating light.When the sensor is placed in a strong airflow or wind,the increase in heat loss of the silicon chip will cause the optical path of the Fabry-Perot interferometer to decrease,resulting in a blue shift of the output spectrum.The higher the wind speed,the greater the wavelength shift.By adjusting the heating power,the response range and sensitivity of the anemometer can be changed.Experimental results show that when the wind speed is 4 m/s,the observed wavelength shift is-0.574 nm.When larger heating power is applied,better sensitivity is expected.The sensor has the characteristics of simple structure,low cost and fast response.