Mathew Jinesh, Semenova Yuliya, Farrell Gerald
Photonics Research Center, Dublin Institute of Technology, Dublin, Ireland.
Appl Opt. 2013 Jun 1;52(16):3884-90. doi: 10.1364/AO.52.003884.
We present a detailed study of a high-sensitivity relative humidity (RH) sensor based on Agarose-coated transmission type photonic crystal fiber interferometer for what is the first time to our knowledge. The sensor shows a wavelength shift of approximately 56 nm for a humidity change of 58% RH. The repeatability of the coating layer formation and the evolution of the coating layers on passing the device though Agarose solution multiple times are studied in detail by observing the spectral shift resulting from the effect on the effective index of the cladding mode. Also, a detailed study is reported of the sensor performance in terms of its sensitivity, repeatability, and long-term stability. The sensor shows a linear response for an RH change in the range of 40%-80% RH with a humidity resolution of 0.017% RH and a higher humidity resolution of 0.007% RH in the range 80%-95% RH. The measurement accuracy of the sensor in the RH range 40%-80% is ±2% RH, and in the range 80%-95%, the accuracy is about ±1% RH. The response time of the sensor is 86 ms, when RH jumps from 50% to 90%. The temperature dependence of the sensor is found to be ~0.27 nm/°C, which is quite small compared to the RH sensitivity of the sensor.
据我们所知，我们首次对基于琼脂糖涂层透射型光子晶体光纤干涉仪的高灵敏度相对湿度（RH）传感器进行了详细研究。该传感器在相对湿度变化58%时显示出约56 nm的波长偏移。通过观察包层模式有效折射率变化引起的光谱偏移，详细研究了涂层形成的重复性以及多次将器件通过琼脂糖溶液时涂层的演变。此外，还报告了对该传感器在灵敏度、重复性和长期稳定性方面的性能进行的详细研究。该传感器在40%-80%相对湿度范围内对相对湿度变化呈线性响应，湿度分辨率为0.017%相对湿度，在80%-95%相对湿度范围内具有0.007%相对湿度的更高湿度分辨率。该传感器在40%-80%相对湿度范围内的测量精度为±2%相对湿度，在80%-95%相对湿度范围内，精度约为±1%相对湿度。当相对湿度从50%跃升至90%时，该传感器的响应时间为86 ms。发现该传感器的温度依赖性约为0.27 nm/°C，与传感器的相对湿度灵敏度相比相当小。
