Enhancement of chemical sensing capability 
in a photonic crystal fiber 
with a hollow high index ring defect at the center

Abstract

A new type of index-guided photonic crystal fiber is proposed to enhance chemical sensing capability by introducing a hollow high index ring defect that consists of the central air hole surrounded by a high index GeO2 doped SiO2 glass ring. Optical properties of the fundamental guided mode were numerically analyzed using the full-vector finite element method varying the design parameters of both the defects in the center and the hexagonal air-silica lattice in the cladding. Enhanced evanescent wave interaction in the holey region and lower confinement loss by an order of magnitude were achieved simultaneously, which shows a high potential in hyper sensitive fiber-optic chemical sensing applications.

Enhancement of the sensitivity of gas sensor based on microstructure optical fiber

“…Index guiding (IG) PCFs [12][13][14][15] and photonic band gap (PBG) PCFs [3,10,16] are used to implement gas sensors. A gas sensor based on hollow core PBGPCFs is proposed in [12,[14][15][16][17] to confine more light into the core which contains gas samples.…”

“…A gas sensor based on hollow core PBGPCFs is proposed in [12,[14][15][16][17] to confine more light into the core which contains gas samples. Since in this fiber, fraction of total power is enhanced by the power of hollow core, the sensitivity is significant [12,[14][15][16][17].…”

“…A gas sensor based on hollow core PBGPCFs is proposed in [12,[14][15][16][17] to confine more light into the core which contains gas samples. Since in this fiber, fraction of total power is enhanced by the power of hollow core, the sensitivity is significant [12,[14][15][16][17]. However, it has two fundamental limitations: narrow transmission spectral band and lack of precise control of waveguide parameters for maintaining the band gap effect [14][15][16][17].…”

“…Since in this fiber, fraction of total power is enhanced by the power of hollow core, the sensitivity is significant [12,[14][15][16][17]. However, it has two fundamental limitations: narrow transmission spectral band and lack of precise control of waveguide parameters for maintaining the band gap effect [14][15][16][17]. To overcome these limitations, index guided PCF is considered as a potential candidate.…”

“…To overcome these limitations, index guided PCF is considered as a potential candidate. But the relative sensitivity of this fiber is very low due to poor interaction between light penetrating into the holes in the cladding and the gas samples inside the holes [14,15].…”