Refractive index sensor of a photonic crystal fiber Sagnac interferometer based on variable polarization states

Abstract

Micron-sized holes distributed in the cross section of photonic crystal fibers allow the integration of the microfluidic analyte and fiber which makes it possible for rapid and effective chemical analysis. The innovation of this paper is that the polarization states of the fiber modes vary with the wavelength. The polarization directions of the two polarized modes are nearly 45 degrees with the horizontal direction at a certain wavelength, then the resonance wavelength will appear by a fiber Sagnac interferometer. The average sensitivity is up to −19040 nm/RIU as the refractive index of the microfluidic analyte varies from 1.33 to 1.37.

A Surface Plasmon Resonance Temperature Sensing Unit Based on a Graphene Oxide Composite Photonic Crystal Fiber

“…The confinement loss (α) is a key parameter index [26] that is proportional to the imaginary part of the effective mode refractive index and represents the ability of an optical waveguide to confine incident light. The equation is shown as formula (4). where λ represents the incident wavelength and imag(neff) represents the imaginary part of the effective refractive index.…”

“…In recent decades, photonic crystal fibers (PCFs) have become a topic of interest in the field of optics [1], [2]. Because of desirable features such as their small size, lightweight, high sensitivity, corrosion resistance, design flexibility, good electrical insulation, and electromagnetic interference resistance [3], [4], PCFs have been extensively applied in biomedicine, environmental monitoring and control, chemical testing, food safety testing [5], [6] and other fields. After several generations of changes in sensing technology, PCF-based surface plasmon resonance (PCF-SPR) sensors have become a compelling focus of research [7].…”

Electrically Tuning Characteristics of LC Selectively Infiltrated PCF Sagnac Interferometer

“…The guiding mechanism can be modulated by infiltrated materials. Photonic crystal fiber based devices such as sensors [2][3][4], optical filters [5] and polarization switch [6] are realized. Fiber devices are novel, compact, sensitive and quick in response, the researches on fiber devices are popular and numbers of studies on PCF infiltrated with functional materials have been explored in last decade [7].…”

Hollow-Core Photonic Crystal Fiber Mach–Zehnder Interferometer for Gas Sensing

“…The spectral response of this hybrid sensor allows multiparameter sensing as it has two distinct interference fringes. The simultaneous measurement capability was reported with an RI measurement resolution of 8.7 E −4 in the RI range of 1.33-1.38 with a temperature sensitivity of 13 pm/ • C. A photonic crystal fiber Sagnac interferometer was developed by Liu et al [16] as an RI sensor, by filling the central hole of the fiber with microfluidic analytes. Fabrication of these sensor types are complicated as filling air holes of a PCF is challenging.…”