We propose and demonstrate a simple highly-sensitive gas pressure sensor based on harmonic Vernier effect. By fusion splicing two hollow silica capillaries, a cascaded Fabry-Perot (FP) cavity is formed. Without special photonics crystal fibers or laser machining involved, the fabrication process is greatly simplified. The interplay between the two interferometers consisting the FP cavity leads to optical Vernier effect. By properly adjusting the length of the silica capillaries harmonic of optical Vernier effect is observed and can be served as a sensitive probe for diagnosing gas pressure. Our results showed a sensitivity of 80.8 pm/kPa from 1 to 101 kPa with good linearity of 99.7%, and a low temperature cross sensitivity of 2.22 kPa/°C, a factor of three lower than that of the microstructure fiber-based gas pressure sensors. Combining both ease of fabrication and high sensitivity, this sensor can be a good candidate for mass production in fields of gas sensing and environmental safety monitoring.

我们提出并演示了一种基于谐波游标效应的简单高灵敏度气压传感器。通过熔接两个中空二氧化硅毛细管，形成了级联的Fabry-Perot（FP）腔。无需特殊的光子晶体光纤或激光加工，制造过程将大大简化。组成FP腔的两个干涉仪之间的相互作用导致光学游标效应。通过适当调节二氧化硅毛细管的长度，可以观察到光学游标效应的谐波，并且可以用作诊断气压的灵敏探针。我们的结果表明，从1到101 kPa的灵敏度为80.8 pm / kPa，线性良好，为99.7％，低温交叉灵敏度为2.22 kPa /°C，比基于微结构的纤维基气体压力低三倍传感器。