Favero F C, Araujo L, Bouwmans G, Finazzi V, Villatoro J, Pruneri V
Pontifical Catholic University of Rio de Janeiro, Rua Marquês de São Vicente 225, 22453-900, Rio de Janeiro, RJ, Brazil.
Opt Express. 2012 Mar 26;20(7):7112-8. doi: 10.1364/OE.20.007112.
All-optical-fiber Fabry-Perot interferometers (FPIs) with microcavities of different shapes were investigated. It was found that the size and shape of the cavity plays an important role on the performance of these interferometers. To corroborate the analysis, FPIs with spheroidal cavities were fabricated by splicing a photonic crystal fiber (PCF) with large voids and a conventional single mode fiber (SMF), using an ad hoc splicing program. It was found that the strain sensitivity of FPIs with spheroidal cavities can be controlled through the dimensions of the spheroid. For example, a FPI whose cavity had a size of 10x60 μm exhibited strain sensitivity of ~10.3 pm/με and fringe contrast of ~38 dB. Such strain sensitivity is ~10 times larger than that of the popular fiber Bragg gratings (1.2 pm/με) and higher than that of most low-finesse FPIs. The thermal sensitivity of our FPIs is extremely low (~1pm/°C) due to the air cavities. Thus, a number of temperature-independent ultra-sensitive microscopic sensors can be devised with the interferometers here proposed since many parameters can be converted to strain. To this end, simple vibration sensors are demonstrated.
研究了具有不同形状微腔的全光纤法布里 - 珀罗干涉仪（FPI）。发现腔的尺寸和形状对这些干涉仪的性能起着重要作用。为了证实分析结果，通过使用特定的拼接程序，将具有大空隙的光子晶体光纤（PCF）与传统单模光纤（SMF）拼接，制造出具有椭球形腔的FPI。发现具有椭球形腔的FPI的应变灵敏度可以通过椭球体的尺寸来控制。例如，一个腔尺寸约为10×60μm的FPI表现出约10.3 pm/με的应变灵敏度和约38 dB的条纹对比度。这种应变灵敏度比流行的光纤布拉格光栅（约1.2 pm/με）大10倍左右，并且高于大多数低精细度FPI。由于有空腔，我们的FPI的热灵敏度极低（约1pm/°C）。因此，由于许多参数可以转换为应变，利用这里提出的干涉仪可以设计出许多与温度无关的超灵敏微观传感器。为此，展示了简单的振动传感器。
