Refractive Index Measurement of Liquids Based on Microstructured Optical Fibers

• Main Authors: Susana Silva, Paulo Roriz, Orlando Frazão
• Format: Article
• Language: English
• Published: MDPI AG 2014-12-01
• Series: Photonics
• Subjects: optical fiber sensors; microstructured fibers; refractive index
• Online Access: http://www.mdpi.com/2304-6732/1/4/516

This review is focused on microstructured optical fiber sensors developed in recent years for liquid RI sensing. The review is divided into three parts: the first section introduces a general view of the most relevant refractometric sensors that have been reported over the last thirty years. Section 2 discusses several microstructured optical fiber designs, namely, suspended-core fiber, photonic crystal fiber, large-core air-clad photonic crystal fiber, and others. This part is also divided into two main groups: the interferometric-based and resonance-based configurations. The sensing methods rely either on full/selective filling of the microstructured fiber air holes with a liquid analyte or by simply immersing the sensing fiber into the liquid analyte. The sensitivities and resolutions are tabled at the end of this section followed by a brief discussion of the obtained results. The last section concludes with some remarks about the microstructured fiber-based configurations developed for RI sensing and their potential for future applications.