the analyte enter the core of the PCF via vertical side
opening channel to measure RI of analytes higher
than that of the background of PCF. We employ a
chemically stable plasmonic (gold) material, and
since the plasmonic material is not directly contacted
by the analyte, the interference effect is minimized.
For the analyte RI of 1.42, the sensitivity, and
resolution of the spectrum have been found to be
11,700 nm/RIU and 8.55 × 10−6 RIU, respectively.
However, our proposed sensor still has the potential
to catch active samples of these chemical and
biological liquids. Various organizations have
released several surface plasmon resonance (SPR)
sensors in the past few years that detect analytes with
a range of 1.33 to 1.41. Micro- fluidic slotted sensors,
internal and external metal- coated PCF-based
sensors, nanowire-based sensors, and D-shaped
configuration-based sensors (A.K. Paul, et., al. 2020)
were derived from it, resulting in five types of PCF-
based SPR sensors.
Mohammad Al Mahfuz et al. In this work, we
have proposed a dual-core photonic crystal fiber (DC-
PCF)-based surface plasmon resonance (SPR)
biocompatible sensor for the refractive index (RI)
sensing of bio-organic molecules and biochemical
analytes in the visible to near-infrared (0.5 to 2 µm)
region. The sensor construction is easy with two
hexagonal ring lattices all with round air aperture.
The use of plasmonic material and an analyte
detecting layer on the outer surface of the fiber allows
practical applications to be made. Gold (Au) with 30
nm of thickness, a noble plasmonic material, is
utilized to excite the plasmons on the surface. It is
also suggested that a thin layer (~5 nm) of TiO2
(titanium oxide) acts as an interlayer cementing the
Au and the silica glass. Based on the mode solver the
finite element method (FEM) is utilized to investigate
the sensor response. Using both amplitude and
wavelength interrogation methods, numerical
findings reveal an optimal wavelength sensitivity
(WS) of as high as 28000 nm/RIU, an optimal
amplitude sensitivity (AS) of 6829 RIU−1, an optimal
amplitude resolution (AR) of 5x10−6 RIU, and a
wavelength resolution (WR) of 3.57x10−6 RIU for
the proposed sensor. Moreover, such a PCF-SPR
sensor, having 2800 RIU−1 as the highest FOMpeak
value, is currently the starkest sensor (M. Al Mahfuz,
et., al 2020).
In this work a novel technique named as 2-D
photonic crystal waveguid (PCW) based cell
detection has been proposed by Abinash Panda et al.
for identifying the nature of either normal or
malignant cells. The proposed metamaterial is
designed with 5 × 5 silicon-based rods on a square
lattice with a central defect and air as the background.
To correctly sense, we classify two sets of live cells:
Group I: Malignant Cell (YD-10B); Group II:
Normal Cell (INOK). Properly adjusting the plane
wave expansion (PWE) method, the electric field
distribution and the peak reflected wavelength have
been achieved in the designed PCW structure.
Accurate identification of normal and malignant cells,
a large number of structural parameters, including
but not limited to lattice spacing, circular rod
diameter, and backdrop material type, are needed.
This MATLAB simulation indicates that yellow
color (i.e. reflected wavelength) belongs to cancerous
cells and orange color (i.e. reflected wavelength)
corresponds to healthy cells. Similarly, the negative
dispersion coefficient, scattering loss, and the
nonlinear coefficient of the proposed structure are
precisely evaluated on normal and malignant cells
separately. Moreover, this proposed sensor has a high
sensitivity of 2360.12 nm/RIU, low resolution of 1.78
× 10−6, and high-quality factor (as high as 99.765)
when differentiating normal and malignant cells (P.P.
Devi and A. Panda, 2020).
Chunlian Cen et al. Here, we propose to use
critical coupling and impedance matching theory to
computationally simulate the perfect absorption of
monolayer graphene. We studied a perfect single-
band absorption of the monolayer graphene by using
the important coupling effect and impedance
matching. Errors from the data fittings remained
within 10%, leading to a high quality factor (Q-factor
= 664.2) absorption spectrum with the absorbance
~100% in the near-infrared range. The position of the
absorption spectrum can be adjusted by changing the
ratio of the air hole radii of the elliptic cylinder to
structural period. The attained S = 342.7 nm/RIU
(refractive index unit) and FOM = 199.2 (figure of
merit) could be achieved by an absorber, which shows
great potential for biosensor technology
development. We hope that our research can serve as
an interesting application for graphene photonics and
optoelectronics. Plasmon metamaterials have
recently been a hot topic due to their unique EM
(electromagnetic) control capability. As such, it is
currently the most studied material due to its optical
and physical properties. The scope of
electromagnetic metamaterials has gone from being
limited to microwave frequency range to terahertz,
infrared, and almost the entire visible light
electromagnetic spectrum as illustrated by the study
(Jiang L et., al.2020) Metamaterial absorbers, on the
other hand, have been shown to improve absorption
in solar, microwave, infrared, and optical systems.