Supersensitive photonic crystal fiber device (PCFD) for the accurate determination of sugar concentration (SC) in an aqueous solution

doi:10.21203/rs.3.rs-5032700/v1

Presently, photonic crystal fiber devices (PCFDs) have gotten a grand importance in various research arenas as a result of their valuable advantages in different applications. One of the most central applications is their usage as detectors to sense several analytes and this is for the reason that these PCFDs are described by high precision and rapidity in sensing process. In this effort, a PCFD is projected as a detector to determine various SCs in an aqueous solution. COMSOL Multiphysics version 5.6 with the finite element approach (FEA) and perfectly matched sheet (PMS) boundary circumstance is expended to build and examine the suggested PCFD. Zeonex matter is exploited in our PCFD owing to its small absorption loss. Several PCFD configurations are studied at x and y-axis. Most optical factors for the suggested PCFD are analyzed and compared together for each SC at the different PCFD configurations and both polarizations. All these factors are analyzed in the frequency scale from 1.0 to 2.5 THz. The highest relative sensitivity (RSE) values are 99.42% for SC of 30% at y-polarization and optimum + 2% configuration. It is proved that enlarging the dimensions of the core zone compared to the zone of the air holes leads to an improvement in the RSE. Also, this PCFD revealed incredibly tiny values of CLS and EMLS. Moreover, all the other optical factors appeared the adeptness of the suggested PCFD in determining the various SCs in the aqueous solution.

PCFD

THz scope

RSE

SC

zeonex

Globally, the THz scope is considered in the frequency group from 0.1 to 10 THz. There are a lot of various applications such as optical sensors [1], spectroscopy [2], imaging [3], security [4], and communication zones [5, 6] are operated and performed in THz scope. Among the infrared and microwave rays, THz waves are endured. Up to date, photonic crystal fiber devices (PCFDs) are amply depleted to sense the biological and chemical samples suitably in the medical and industrial sections. In recent times, a lot of the academics are employed PCFDs based on the THz technology to detect various analytes efficaciously [7, 8]. Today, several sorts of background substances for instance Topas, Teflon and Zeonex are very proper in PCFDs to diminish the confinement loss (CLS) and effective material loss (EMLS). Therefore, investigators accomplished numerous PCFDs with unique optical assets for example the greater relative sensitivity (RSE) [9], small CLS [10], higher effective area (EA) [11] via these substances. In the earlier review, A lot of scholars realized better performance factors including CLS, RSE, EA, and EMLS etc. in their proposed PCFDs. PCFD structure was advised in ref. [12] which included circular gaps with elliptical core. The RSE level of this PCFD was 40%. Another PCFD was suggested by M.Arif.et al. [13] and achieved RSE nearly 41%. R.T. In ref. [14], a PCFD was stated with RSE of 43%. However, this PCFD was given high CLS and was not reported other important performance factors. K. Ahmed et al. were suggested novel PCFD with the RSE of 57%. The CLS with the previous design was high [7]. In ref. [15], a PCFD was suggested for detection chemical analytes with the RSE of 66%. But others performance characteristics such as EMLS and

CLS were not offered suitably. In the review of aforementioned items and other articles [16–19], it is be observed that the RSE value is miserable. Thus, this soft value of RSE is not simply to sense the analytes in the various areas. Subsequently, it is a good occasion to create a novel PCFD with high RSE and low CLS in the THz scope for bio-sensing purposes.

Here, it is suggested a novel PCFD with a square core and rectangular holes in cladding area to determine of various sugar concentrations (SCs) in an aqueous solution. At operating frequency of 2.0 THz, the projected PCFD structure reveals high RSE with low CLS and EMLS. Other parameters such as EA, NA and Bi are explored carefully. Both x and y-directions are considered. Furthermore, 3 situations of PCFD are checked. These situations are optimum, -2% optimum and + 2% optimum.

Lately, to invent and design the PCFD, COMSOL Multiphysics has been frequently applied and FEA is worked to analyze the functioning of the offered PCFD. The view of the PCFD with all materials used is displayed in Fig. 1(a). The core is a square form with a dimension of (L). The shape of cladding hole is rectangular. The width of all these holes have the same width (WR) and the length of each rectangle is depicted in Table 1. D is the space among any two holes in cladding scope which is matching and identical. A perfectly matched sheet (PMS) is treated as 10% of the PCFD’s total radius. ROF is the radius of fiber which contains PMS.

To determine the diverse levels of SC in an aqueous solution, it is required to put within the core gap individually. After that, the model is run for various working frequencies. The enormously well mesh involving of 13920 domain components and 1338 boundary components is operated for our model and is represented in Fig. 1(b). Due its unchanged RI during the THz zone and seriously bio- harmonious in addition to approvingly temperature oblivious, Zeonex is depleted in the projected PCFD as a fiber background. Table 1 indicates all dimensions concerning the projected PCFD.

Today, numerous fabrication systems have been stated to design the various PCFD structures, e.g. sol-gel, extrusion, capillary piling, 3D printing, etc. It is worth to indicate that capillary piling and sol-gel system are massively exploited to invent circular holes [20] while asymmetric (rectangular and square) holes can be designed and performed via extrusion [21] and 3D printing [22] techniques. Consequently, for the fabrication of the projected PCFD, the 3D printing and extrusion approaches are desirable .

Table 1

Dimension used for the suggested PCFD.
ROF	1250 µm
PML	125 µm
L (optimum)	660 µm
L (optimum − 2%)	646.8 µm
L (optimum + 2%)	673.2 µm
WR	320 µm
LR1	2.5L
LR2	1.25L
D	20 µm
$\:{\text{n}}_{\text{Z}\text{e}\text{o}\text{n}\text{e}\text{x}}$	1.53
$\:{{\alpha\:}}_{\text{Z}\text{e}\text{o}\text{n}\text{e}\text{x}}$	$\:0.2\:{\text{c}\text{m}}^{-1}$

The numerical inspection is realized by devoting the PMS to the border term and the full vector FEA that is widely exploited. By this FEA, the various characteristics of PCFD are inspected and considered.

To study the sensing capability of any PCFD, the RSE which is the key parameter must be evaluated and determined. This is the main sensing implementation indicator that appraises the attendance and amount of analytes devoted via the core. The RSE is calculated as [23]

$$\:RSE=\frac{{n}_{a}}{{n}_{ef}}PF,\:\%$$

1

Here, $\:{n}_{a}$ act for the RI of the analyte, and $\:{n}_{ef}$ infers the RI of effective modal. $\:PF$ denotes the power fraction which is estimated as [23]

$$\:PF=\frac{\underset{analyte}{\int\:}Re\{{E}_{x}{H}_{y}-{H}_{x}{E}_{y}\}dxdy}{\underset{total}{\int\:}Re\{{E}_{x}{H}_{y}-{H}_{x}{E}_{y}\}dxdy},\:\%$$

2

Here, H_x, H_y and E_x, E_y are the transverse electric and magnetic fields in x and y directions respectively. Afterward, laying the values of PF, n_a and n_ef in Eq. (1), we can acquire RSE trend as a function of frequency. At this point, $\:{n}_{ef}^{x}$ is the RI of the PCFD in the x axis and $\:{n}_{ef}^{y}$ is the RI of the PCFD in y axis [24].

Generally, the effective area (EA) be suspended with the electric field and implies that in which quantity of the waves is spreading exterior of the core gap and the well sensitive zone for an analyte. The EA is considered as [25]

$$\:EA=\frac{{\left(\int\:\left|{E}^{2}\right|dxdy\right)}^{2}}{\int\:\left|{E}^{4}\right|dxdy},\:{\mu\:m}^{2}$$

3

where, $\:E\:$are the transverse electric fields that are embarrassed in an integral portion of the respected PCFD.

The numerical aperture (NA) is extremely significant factor in PCFDs. It is the degree of the angular agreement of received light for a PCFD. This supervisory characteristic is dependent on the geometric configuration of the PCFD and is frequently examined by using the following equation [26]

$$\:NA={(1+\pi\:{f}^{2}{A}_{eff}/{c}^{2})}^{-0.5}$$

4

Here,$\:\:c$ is the light velocity, and$\:\:f$ is the operating frequency.

Furthermore, 2 kinds of familiar losses are considered for the offered PCFD which is EMLS and CLS. These losses arise in any class of PCFD. The EMLS is the symptom of power loss because of the background substance of the PCFD and the CLS denotes the power loss as a result of the air gaps about the core hole. The EMLS is calculated as [27],

$$\:EML=\frac{\sqrt{\frac{{\epsilon\:}_{0}}{{\mu\:}_{0}}}\:\underset{material}{\int\:}{\eta\:}_{material}{\alpha\:}_{material}{\left|E\right|}^{2}dA}{\left|\underset{all}{\int\:}\frac{1}{2}(E\times\:{H}^{*})\widehat{z}dA\right|\:},\:{cm}^{-1}$$

5

Here,$\:\:{\epsilon\:}_{0}$ is the relative permittivity and $\:{\mu\:}_{0}$ are the relative permeability of air. $\:{\eta\:}_{material}$ signify the RI and$\:{\:\alpha\:}_{material}$ signify the bulk absorption aspect ($\:{cm}^{-1}$) for the Zeonex.

CLS is depended upon the core sponginess in addition to the quantity of gaps in the cladding. It is computed by the imaginary part of the complex RI as [28]

$$\:CL=8.686\times\:{k}_{0}\times\:Img\left({n}_{ef}\right)\times\:{10}^{-2},\:{cm}^{-1}$$

6

where,$\:\:Img\left({n}_{ef}\right)$ is the imaginary portion of RI for the offered device and $\:{k}_{0}$ = 2π (λ)⁻¹, λ is the waves wavelength.

Here, the data harvested from FEA-based software are devoted to recognize a number of performance factors such as RSE, CLS, EMLS, EA in addition to birefringence of the projected PCFD via COMSOL Multiphysics. The frequency scale (1.0-2.5 THz) is used in the suggested PCFD and 2.0 THz is the performing frequency. Three situations of core width are considered for 3 concentrations: SC = 0%, 15% and 30% with RI 1.3282, 1.3558, and 1.377 of [29]. The RI of sample is modified as the solution involving various SCs and then the PCFD can be determined the SC. The light propagation through the different SCs is described in Fig. 2 (SC = 0 %), Fig. 3 (SC = 15 %), and Fig. 4 (SC = 30 %) for both x and y directions. A very minor quantities of light moved exterior of the core which implies the loss amount is tiny. The red zone is displaying the top confinement of light. The power is progressively shrinking in the direction of the core limit. The direction of light propagation is represented as a red arrow.

The n_eff with frequency is analyzed for the projected PCFD with x and y polarization for various chosen SCs, at optimum, optimum -2% and optimum +2% case. In x and y-direction for SC = 0.0 %, SC = 15 % and SC = 30 %, Fig. 5 displays n_eff versus various frequency. Undoubtedly, as the frequency rises the n_eff boost for both x and y-direction. Noticeably, the optimum -2% item has a greater n_eff than that happens in the optimum and optimum +2% situation for all SCs and polarizations. The values of n_eff that existed in x-polarization are higher than the values that performed in y-direction for the various suggested PCFDs. At f = 2.0 THz, Table 2 displays the n_eff values for the projected PCFD at various polarizations and different SCs. Obviously, n_eff values in each case are reasonably close to the RI values of analyte. Furthermore, as the RI of the analyte rises, n_eff enlarges in all PCFDs and polarizations.

Table 2. The neff values for the suggested PCFD at 2 THz

SC	Polarization mode	PCFD structure	n_eff
0%	x-Pol	Opt. +2 %	1.32134
		Opt.	1.32245
		Opt. -2 %	1.32522
	y-Pol	Opt. +2 %	1.32131
		Opt.	1.32244
		Opt. -2 %	1.3254
15%	x-Pol	Opt. +2 %	1.34884
		Opt.	1.34959
		Opt. -2 %	1.35117
	y-Pol	Opt. +2 %	1.34882
		Opt.	1.34957
		Opt. -2 %	1.35121
30%	x-Pol	Opt. +2 %	1.37
		Opt.	1.37055
		Opt. -2 %	1.37162
	y-Pol	Opt. +2 %	1.36998
		Opt.	1.37054
		Opt. -2 %	1.37162

For the 3 suggested cases (optimum, optimum +2%, and optimum -2% case), the effective area (EA) against frequency for the suggested PCFD with several SCs is respected in the frequency scale from 1.0 THz to 2.5 THz for both x and y directions. Figure 6 displays EA behavior for SC = 0.0%, SC = 15% and SC = 30% in x and y-polarization at the various PCFDs that were declared previously. EA drops with the frequency growing mostly. It can be explicated as follows: as the frequency rises, the confinement of light inside the core enlarges, which leads to a reduce in EA. Consequently, lesser values of the EA are required in detecting circumstances. Optimum -2% item provided the least EA values compared to the other 2 cases in both direction of the polarization, and for all SCs. At 2.0 THz and in both polarizations, Table 3 exhibits EA values for the suggested PCFDs with different SCs. Clearly, for all PCFDs and polarizations at 2.0 THz, the EA values fall when the PCFD nature modifies from an optimum +2% to the optimum then optimum -2% case, respectively.

Table 3. The EA values for the suggested PCFD at 2 THz.

SC	Polarization mode	PCFD structure	EA (µm²)
0%	x-Pol	Opt. +2 %	263377.23
		Opt.	253209.93
		Opt. -2 %	159300.36
	y-Pol	Opt. +2 %	269550.80
		Opt.	227746.60
		Opt. -2 %	201620.01
15%	x-Pol	Opt. +2 %	262248.83
		Opt.	240125.63
		Opt. -2 %	182126.31
	y-Pol	Opt. +2 %	265412.08
		Opt.	254524.18
		Opt. -2 %	212078.16
30%	x-Pol	Opt. +2 %	260917.21
		Opt.	246561.32
		Opt. -2 %	201381.08
	y-Pol	Opt. +2 %	262681.32
		Opt.	255408.90
		Opt. -2 %	222502.25

Here, NA is examined at various frequencies for the planned PCFD. The chosen cases of PCFD are respected at x and y-polarization. The computations of NA at chosen PCFD cases for various SCs is represented in Fig. 7.

For both x and y-directions, as the optimum -2% case is operated to the PCFD, the values of NA are higher than the optimum and optimum +2% case, respectively. In general, as the frequency enlarges, the NA values diminish for all PCFDs. The basis for the lessening in NA values with growing frequency is that the NA depends on the EA which falls with a rise in frequency. Great values of NA are helpful in sensing purposes. At 2.0 THz for various PCFDs, Table 4 displays NA values at both polarizations. It can be understood that at the optimum -2% situation has greatest NA values compared with those performed in the optimum and optimum +2% situation.

Table 4. The NA values for the suggested PCFD at 2 THz

SC	Polarization mode	PCFD structure	NA
0%	x-Pol	Opt. +2 %	0.16264
		Opt.	0.16578
		Opt. -2 %	0.20734
	y-Pol	Opt. +2 %	0.16081
		Opt.	0.17453
		Opt. -2 %	0.18513
15%	x-Pol	Opt. +2 %	0.16298
		Opt.	0.17011
		Opt. -2 %	0.19443
	y-Pol	Opt. +2 %	0.16203
		Opt.	0.16536
		Opt. -2 %	0.18066
30%	x-Pol	Opt. +2 %	0.16338
		Opt.	0.16794
		Opt. -2 %	0.18524
	y-Pol	Opt. +2 %	0.16285
		Opt.	0.16509
		Opt. -2 %	0.17652

With various PCFDs which are optimum -2%, optimum and optimum +2% case, the PF through the suggested PCFD core is studied for various SCs injected into the core. Figure 8 displays PF for SC = 0.0%, SC = 15% and SC = 30 %. For both polarizations, when the optimum +2% case is operated to the suggested PCFD, the PF values are superior than that in the optimum and optimum -2% situation. Clearly, the PF profile of optimum -2% situation show a decrease in the value of the PF with the rise in frequency. For x direction and at optimum +2% case , highest PF of the projected PCFD is 98.32 %, 98.69 % and 98.90 % for SC = 0.0%, SC = 15% and SC = 30%, respectively. For y-direction and at optimum +2% case, the greatest PF is 98.31%, 98.70% and 98.91% for SC = 0.0%, SC = 15% and SC = 30%, respectively. At f = 2.0 THz, Table 5 displays PF values for various PCFDs and at both polarization directions. As the RI of the SC grows, the value of PF rises. Also, Table 5 proved the case of optimum +2% has PF better than the values that performed in optimum and optimum -2%, respectively.

Table 5. The PF values for the suggested PCFD at 2 THz

SC	Polarization mode	PCFD structure	PF (%)
0%	x-Pol	Opt. +2 %	98.32
		Opt.	95.14
		Opt. -2 %	84.50
	y-Pol	Opt. +2 %	98.31
		Opt.	95.37
		Opt. -2 %	83.00
15%	x-Pol	Opt. +2 %	98.69
		Opt.	96.82
		Opt. -2 %	91.22
	y-Pol	Opt. +2 %	98.70
		Opt.	96.73
		Opt. -2 %	90.68
30%	x-Pol	Opt. +2 %	98.90
		Opt.	97.52
		Opt. -2 %	93.98
	y-Pol	Opt. +2 %	98.91
		Opt.	97.49
		Opt. -2 %	93.75

For both polarizations, the modification in RSE with frequency for the recommended PCFD with various chosen PCFD configurations are investigated. The RSE behavior with the frequency for various SCs is shown in Fig. 9. Obviously, when the optimum +2% situation is employed in the suggested PCFD, the values of RSE are superior than those corresponding to the optimum and optimum -2% situation, respectively.

At x-polarization, the greatest values of RSE are (98.83%, 99.20% and 99.41%) and at y-polarization are (98.83%, 99.21% and 99.42%) for (SC = 0.0%, SC = 15% and SC = 30%), respectively. These highest values of RSE are attained for optimum +2 % situation. At 2.0 THz, Table 6 exhibits the RSE for various PCFDs and both polarizations. From this table, the RSE values of those PCFDs are very great and this is extremely suitable in sensing functions. Clearly, as the RI of the sensing medium rises, the RSE values boost.

Table 6. The RSE values for the suggested PCFD at 2 THz

SC	Polarization mode	PCFD structure	RSE (%)
0%	x-Pol	Opt. +2 %	98.83
		Opt.	95.56
		Opt. -2 %	84.69
	y-Pol	Opt. +2 %	98.83
		Opt.	95.79
		Opt. -2 %	83.17
15%	x-Pol	Opt. +2 %	99.20
		Opt.	97.26
		Opt. -2 %	91.53
	y-Pol	Opt. +2 %	99.21
		Opt.	97.18
		Opt. -2 %	90.99
30%	x-Pol	Opt. +2 %	99.41
		Opt.	97.98
		Opt. -2 %	94.34
	y-Pol	Opt. +2 %	99.42
		Opt.	97.95
		Opt. -2 %	94.12

With selected PCFD configurations stated previously, EMLS of the suggested PCFD is inspected. Both polarizations are respected. The behavior of EMLS with frequency for various SCs is appeared in Fig. 10. From these figures, in x and y-directions, the modification in EMLS with frequency is exhibited as a parabolic curve trend at optimum -2% situation more than that in the optimum and optimum +2% situation.

Furthermore, optimum -2% case has the highest EMLS values compared with the other two situations for both polarizations. At f = 2.0 THz, Table 7 displays the values of EMLS for various SCs at optimum +2%, optimum and optimum -2% case. It is found that as the RI of the sensing medium raises, the values of EMLS reduces in each design. It is discerned that x polarization for all SCs has EMLS values lesser than those developed in y-polarization for optimum +2%, and optimum -2% situations. Also, it is discovered that x polarization for all SCs has EMLS values greater than those developed in y-polarization for optimum situations.

Table 7. The EMLS values for the suggested PCFD at 2 THz

SC	Polarization mode	PCFD structure	EMLS (cm^-1)
0%	x-Pol	Opt. +2 %	0.00189
		Opt.	0.00726
		Opt. -2 %	0.02718
	y-Pol	Opt. +2 %	0.00194
		Opt.	0.00678
		Opt. -2 %	0.03031
15%	x-Pol	Opt. +2 %	0.00148
		Opt.	0.00461
		Opt. -2 %	0.01484
	y-Pol	Opt. +2 %	0.00150
		Opt.	0.00482
		Opt. -2 %	0.01597
30%	x-Pol	Opt. +2 %	0.00124
		Opt.	0.00356
		Opt. -2 %	0.00998
	y-Pol	Opt. +2 %	0.00125
		Opt.	0.00367
		Opt. -2 %	0.01048

At various PCFD configurations and different polarizations for each SC, the modification of CLS with frequency in the THz scope of the suggested PCFD is studied. The CLS values with frequency for various SCs are shown in Fig. 11. From these figures, it is observed that the values of CLS are very tiny in frequencies from 1.0 to 2.5 THz, and this trend is very valuable for various sensing usages, as it means satisfactory confinement of light in the core gap where the sensing action takes place. The left panel of figurer displays the modification of CLS in x direction for the situations of optimum -2%, optimum and optimum +2%, and the right panel displays the modification of CLS in y-direction for the same situations. Clearly, it is achieved that the CLS for the several SCs diminishes snappishly with frequency and then convert near zero. At 2.0 THz and for different SCs, Table 8 presents the CLS values at x and y-directions. The three picked PCFD configurations are respected. Observably, the top values of CLS is appeared at optimum situation for x-direction while at optimum -2% situation for y-direction.

Table 8. The CLS values for the suggested PCFD at 2 THz

SC	Polarization mode	PCFD structure	CLS ×10^-12 (cm^-1)
0%	x-Pol	Opt. +2 %	3.34988
		Opt.	1.58564
		Opt. -2 %	21.9331
	y-Pol	Opt. +2 %	0.76317
		Opt.	7.71228
		Opt. -2 %	3.81287
15%	x-Pol	Opt. +2 %	0.55121
		Opt.	1.00134
		Opt. -2 %	2.44351
	y-Pol	Opt. +2 %	0.13711
		Opt.	0.31510
		Opt. -2 %	0.52058
30%	x-Pol	Opt. +2 %	0.13448
		Opt.	0.23857
		Opt. -2 %	0.46602
	y-Pol	Opt. +2 %	0.04810
		Opt.	0.07259
		Opt. -2 %	0.10827

Ultimately, the adaptation of birefringence with the frequency for the suggested PCFD is considered at various polarizations and PCFD structures. At optimum -3%, optimum and optimum +3% situations for the chosen SCs, Fig 12 exhibits the birefringence values of the suggested PCFD. Clearly, the top birefringence is occurred at 1.0 THz in optimum and optimum +2% siuations for all nominated SCs. For optimum -2% situation, the top birefringence is appeared at 2.4 THz, 2.5 THz and 1.0 THz for SC = 0.0%, SC = 15% and SC = 30%, respectively. Also, the birefringence values at optimum -2% case are permanently superior than that of optimum and optimum +2% situation. At 2.0 THz and for the chosen SCs, the values of birefringence for the suggested PCFD are described in Table 9. Unmistakably, as the RI of analyte rises, the birefringence shrinkages at f = 2.0 THz for optimum +2% and optimum -2% situation while enlarges at optimum situation. Table 10 compares the projected PCFD with predominant PCFDs. This table reﬂects the success of the recommended PCFD and proves superlative efficiency in determination of the SC in an aqueous water.

Table 9. The Bi values for the suggested PCFD at 2 THz

SC	PCFD structure	Bi ×10^-5
0%	Opt. +2 %	2.784
	Opt.	0.313
	Opt. -2 %	17.95
15%	Opt. +2 %	2.567
	Opt.	1.455
	Opt. -2 %	4.035
30%	Opt. +2 %	2.355
	Opt.	1.889
	Opt. -2 %	0.204

Table 10. Comparison of the optical factors of the projected PCFD with difference PCFDs.

Ref	Freq.	ClS (cm^-1)	PF (%)	RSE (%)	EA (µm²)	NA	EMLS (cm^-1)	Bi
[30]	1 THz	2.11×10-14	-	96.25	1.29×106	-	9.16×10-4	-
[31]	0.7 THz	0.15×10-6	26	64	4.4×105	-	0.035	0.06
[32]	2 THz	3.11×10-14	-	93.5	2.2×105	-	-	-
[33]	2.5 THz	9.5×10-15	-	98.67	334610	-	0.00779	-
[34]	2 THz	1.73×10-8	-	65.43	-	-	-	-
[35]	1.8 THz	4.87×10-11	-	91.5	397340	-	0.0039	-
[36]	1.6 THz	1.7×10-9	-	85.7	69800	-	-	-
This paper	2 THz	4.810×10^-14	98.91	99.42	262681.32	0.16285	0.00125	2.355

A PCFD was studied for the determination of SC in an aqueous solution. FEM and PMS boundary circumstances were operated to simulate and analyze the offered PCFD using COMSOL Multiphysics version 5.6. The offered PCFD was considered from a number of features, where the two kinds of polarization were respected, and different PCFD configurations with various core dimensions were investigated. In each configuration, all performance factors including RSE, PF, CLS, EMLS, EA, NA and Bi were decided carefully. All the aforementioned factors were compared at 2.0 THz. The projected PCFD revealed its high detecting precision and provided admirable outcomes. For both polarizations, the numerical findings of the projected PCFD indicated that as the dimensions of the core gap augment, the values of performing factors boost for all different SCs. The chief RSE have been acquired at y-direction in the configuration of an optimum +2% of the suggested PCFD, and this value was 99.42 % for SC of 30%. Furthermore, various PCFD configurations were demonstrated incredibly small values of CLS and EMLS . In addition to the exceptional findings exhibited by this PCFD in the determination of SC in an aqueous solution, the simplicity of the projected PCFD structure certifies that it is easy to build at low costs.

Authors Contributions:

Conceptualization and design, Malek G. Daher; Methodology, Investigation, Malek G. Daher, Osama S. Faragallah, and Mahmoud M. M. Abu Hasanein; Software, Mahmoud M. M. Abu Hasanein and Abdulkarem H. M. Almawgani; Visualization, Writing-original draft, Ammar Armghan, Shivam Singh, Osama S. Faragallah and Anurag Upadhyay; Funding acquisition, Osama S. Faragallah; Supervision, Malek G. Daher.

Acknowledgement:

The authors extend their appreciation to Taif University, Saudi Arabia, for supporting this work through project number (TU-DSPP-2024-40).

Funding: This research was funded by Taif University, Saudi Arabia, Project No. (TU-DSPP-2024-40).

Availability of Data and Material: Simulation software.

Data Availability: The datasets generated and analyzed during the current study are available from the corresponding author on reasonable request.

Ethics Approval: Not applicable.

Consent to Participate: Not applicable.

Consent for Publication: Not applicable.

Conflict of interest: No competing interests

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No competing interests reported.

Supersensitive photonic crystal fiber device (PCFD) for the accurate determination of sugar concentration (SC) in an aqueous solution

Status:

Version 1

Abstract

Figures

1. Introduction

2. Model design

3. Methodology and performing factors

4. Results and discussion

Conclusion

Declarations

References

Additional Declarations

Status:

Version 1