Slotted photonic crystal fiber-based plasmonic biosensor

Abstract

An optical fiber having the properties of photonic crystal and offering new diversity and features beyond a conventional optical fiber is the photonic crystal fiber (PCF). In this paper, a simplified version of a highly sensitive plasmonic sensor, called a “slotted PCF based plasmonic biosensor,” is studied numerically with asymmetric air holes using the finite element method. From numerical records through the interrogation method, the maximum obtained wavelength sensitivity and amplitude sensitivity are 22000 nm/RIU and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mn>1782.56</mml:mn> <mml:mspace width="thinmathspace"/> <mml:mspace width="thinmathspace"/> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">R</mml:mi> <mml:mi mathvariant="normal">I</mml:mi> <mml:mi mathvariant="normal">U</mml:mi> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> , respectively, with a maximum wavelength resolution of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mn>4.54</mml:mn> <mml:mo>×</mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>−</mml:mo> <mml:mn>6</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> <mml:mspace width="thinmathspace"/> <mml:mspace width="thinmathspace"/> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">R</mml:mi> <mml:mi mathvariant="normal">I</mml:mi> <mml:mi mathvariant="normal">U</mml:mi> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> RIU for the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>y</mml:mi> </mml:math> -polarized mode. Finally, optimization of the sensor performance is scrutinized, and the effect of different parameters is studied with proper resonance wavelength curve fitting. The design structure of the fiber is simple, symmetrical, easy to fabricate, and cost effective and has higher sensitivity than other PCF based sensors. Having a symmetric orientation of air holes, classic geometric structure, and higher sensitivity, it has the capability to be used in sensing applications, refractive index detection, and identification of biochemicals, biomolecules, and other analytes.

Topics & Concepts