Refractive index measurement using photonic crystal fiber-based Fabry-Perot interferometer

Abstract

We have constructed a novel refractive index (RI) sensor based on a fiber optic Fabry-Perot interferometer (FPI) by splicing a section of hollow core fiber between a single-mode fiber and a photonic crystal fiber (PCF). Owing to the air holes in the cladding of the PCF, various substances, such as liquids and gases with different RI, can enter or leave the in-fiber air cavity, which makes the device usable as a refractometer. In this paper, the fiber optic FPI sensor has been used to monitor the RI changes of air with different pressures, and the experimental results show that such a sensor has an RI sensitivity of 805.1 microm/RIU, and hysteresis is not observed. Moreover, the easy fabrication method gives the in-fiber refractometer many potential applications in the sensing field.

Photonic Crystal Fiber–Based Interferometric Sensors

“…A RI sensitivity of 851 nm/RIU and a low cross sensitivity with temperature of~3.2 Â 10 À7 RIU/ C was obtained. A short section of hollow fiber had been sandwiched between single mode fiber (SMF) and solid core (SC) PCF [11]. By taking advantage of the air holes in PCF, air was allowed to infiltrate the PCF cavity and the RI changes under different pressures were measured.…”

Study on fiber-optic low-coherence interferometric and fiber Bragg grating sensors

“…Taking advantage of their unique characteristics in confining light, we reported novel PCF-based F-P interferometers for sensing of strain, refractive index and temperature [11][12][13][14][15], for the first time. To measure the stress of engine blades, we designed a hollow-core PCF based F-P sensor which could survive high temperatures of up to 600 ℃ [11].…”

“…One was formed by splicing a section of endlessly PCF between two SMFs. The other was formed by cascading a section of hollow-core fiber and a normal PCF to an SMF [13,14]. These two types of sensors have refractive index resolution of 210 -5 for glycerin solution and resolution of 1.610 -5 for air, respectively.…”

Highest achievable detection range for SPR based sensors using gallium phosphide (GaP) as a substrate: a theoretical study

“…By measuring the change in the resonance wavelength, the corresponding change in the refractive index of the medium can be measured. There are other techniques also for measuring changes in the refractive index such as the Mach-Zhander interferometer and Febry-Perot interferometer, however, SPR sensors are also getting progressed with the equal pace such as in the sensing of hydrogen gas using palladium [13][14][15].…”