Photonic Crystal Sensor Research Articles

A highly sensitive quadruple D-shaped open channel photonic crystal fiber plasmonic sensor: A comparative study on materials effect

A highly sensitive dual-polarized 'X' oriented quadruple D-shaped open channel photonic crystal fiber (PCF) based surface plasmon resonance (SPR) sensor for various analyte detection is proposed in this paper. Gold is taken as a plasmonic material for its stability and compatibility. Silicon nitride (Si3N4) and titanium oxide (TiO2) has been used separately as an adhesive layer of gold to elevate the sustainability of the evanescent field. This paper shows a comparative study and inspects the effect of sensing performance between Si3N4 and TiO2 as an adhesive layer of gold. Numerical investigations have been followed up using the finite element method (FEM). For practical feasibility, analyte and plasmonic materials have been placed at the outer surface of the sensor. After watchful investigation, the maximum wavelength sensitivities of 21,000 nm/RIU (Refractive Index Unit) and 18,000 nm/RIU have been found for the y-polarization when using TiO2 and Si3N4, respectively. The highest amplitude sensitivities are of 914RIU−1 and 625RIU−1 for TiO2 and Si3N4, respectively. Furthermore, minimum wavelength resolutions of 4.76 × 10−6 RIU and 5.55 × 10−6 RIU have been observed in y-polarization for TiO2 and Si3N4, respectively. The sensor evinces a maximum figure of merit (FOM) of 236RIU−1 for TiO2. This sensor has the analyte sensing range of 1.31–1.38RI (Refractive Index) for TiO2 and 1.32–1.39RI for Si3N4. The sensor also delivers low confinement loss for Si3N4 and TiO2, which certifies viability in fabricating the design. Recognizing this sensor’s wavelength sensitivity, amplitude sensitivity, and sensing RI range, it could be a promising candidate for detecting different liquid analytes with excellent accuracy.

Photonic Crystal Fiber Sensor for X Ray Approximate Effective Radiation Dose

X-ray is electromagnetic wave pass through all human tissue and show tissue image by black and white, and the explosion for x ray in short treatment may cause cancer, Photonic crystal fiber used as detector for x- ray approximate effective radiation dose for human bone for spine x- ray 1.5 mSv which need 6month to repeat the exposure and extremity (foot, hand and etc.) x-ray 0.001 mSv need to 3 hours to repeat exposure , the change in x ray dose can be detected by measuring the change in wavelength shifting of laser 450nm which pass through photonic crystal fiber and effected by the emission of x-ray to record the small change in x-ray dose and save the human from radiation and this sensor is small compact and easy to use and have high sensitivity for x -ray used to measure the bone x-ray as its value lower than other x-ray used in others tissue. Index Terms— photonic crystal fiber, sensor ,x- ray, laser.

Design and analysis of dual polarized Au and TiO2-coated photonic crystal fiber surface plasmon resonance refractive index sensor: an extraneous sensing approach

In this work, a photonic sensor based on photonic crystal fiber and surface plasmon resonance to analyze the refractive index (RI) of analytes varying from 1.440 to 1.480 is presented. A dual hexagonal lattice of air holes is reported in this proposed sensor design. The combination of titanium dioxide (TiO2) and gold (Au) is used as a plasmonic material in this sensor. The sensing capability of the proposed sensor is inspected in terms of wavelength sensitivity, amplitude sensitivity, sensor resolution, linearity of resonance wavelength, and figure of merit (FOM). Theoretical analysis of the sensor is performed for both quasi TM mode and quasi TE mode. Numerical investigation shows that wavelength sensitivity of 12 , 000 nm RIU − 1, is obtained for both TM mode and TE mode using the wavelength interrogation method. AS of 3307 and 3619 RIU − 1 is obtained for TM mode and TE mode, respectively, using the amplitude interrogation method. A maximum sensor resolution of 8.33 × 10 − 6 RIU is obtained for both TM mode and TE mode, respectively. The linear relationship of resonant wavelength with RI produces R2 = 0.9991 and R2 = 0.9970 for degree 2, for TM mode and TE mode, respectively. The FOM obtained from the proposed sensor is 139.53 and 187.50 for TM mode and TE mode, respectively.

Design and analysis of a single elliptical channel photonic crystal fiber sensor for potential malaria detection

Malaria is a mosquito-borne disease caused by unicellular hemoparasites of the genus Plasmodium that results in the death of over one million people worldwide every year. Early diagnosis plays a key role in the treatment of infected patients and can reduce the mortality rate. This work proposes a simple designed photonic crystal fiber (PCF) sensor for detecting malarial infection using the refractive index (RI) of red blood cells (RBCs). The initial structure of the PCF sensor consists of double loops of circular air holes arranged in a hexagonal formation. A horizontal elliptical channel in the center of the fiber contains the RBCs sample. The sensor’s response was observed from the shift of the transmission spectra due to change in the RI of RBCs during different life stages of the parasite. Model parameters (transmission length, pitch, air hole diameter, and eccentricity of the elliptical channel) of the proposed sensor were optimized to obtain the best possible response. The highest spectral sensitivities were obtained about 11,428.57 nm/RIU, 9473.68 nm/RIU, and 9655.17 nm/RIU for the ring, trophozoite, and schizont phases of the parasite, respectively. Due to its high sensitivity, easy identification capability, and short transmission length, this sensor can be utilized as a cost-effective and useful device for malaria diagnosis.

Design and optimization of index guiding photonic crystal fiber-based gas sensor

Hydrogen sulfide(H2S) and methane(CH4) are flammable, toxic, and colorless gases that exist in oil rigs/refineries. The PCF based gas sensors can detect the concentration of chemical materials such as hydrogen sulfide and methane. This paper presents a hexagonal PCF for sensing these gases. Characteristics of the proposed structure have been investigated for the wavelength range of 1.1 μm–1.6 μm using the full vector finite element method (FEM). The numerical results show that using non-circular holes around the central ring holes and a higher number of ring holes improves sensitivity and confinement loss respectively. Eventually, the relative sensitivity is enhanced to 62.07% and 67.07% and also the confinement loss 2.33 × 10−9dB/m and 8.61 × 10−5dB/m at the wavelength of 1.33 μm and λ = 1.578 μm at which the CH4 and H2S have a strong absorption line, respectively.

Numerical exploration of external sensing scheme based photonic crystal fiber surface plasmonic sensor with different noble plasmonic materials and their alloys

The selection of appropriate plasmonic material is extremely crucial for getting good sensing performance from photonic crystal fiber-based surface plasmon resonance (PCF-SPR) sensors. The numerical investigation of PCF-SPR sensors is still limited to conventional plasmonic materials in most existing studies. Recent researches show that some alloys can also be potential candidates as plasmonic materials for their remarkable plasmonic characteristics. This article presents a numerical analysis of a simple designed external sensing scheme based PCF-SPR sensor employing different noble plasmonic materials and their alloys. The sensor's design is kept very simple to ease the fabrication complexity, and the sensing ingredient is placed outside of the main structure. To investigate the sensing performance of the sensor, we have chosen gold, silver, and copper as noble plasmonic materials and gold-silver (30 %–70 %), gold-silver (70 %−30 %), and copper-zinc (90 %−10 %) as alloys. From the obtained results, it is observed that the reported sensor shows maximum amplitude sensitivity (AS) of 9759.00 RIU−1 and figure of merit (FOM) of 923.07 RIU−1 when the silver coating is used. Moreover, the reported sensor shows maximum spectral sensitivity (SS) of 26,000 nm/RIU and resolution of 3.84 × 10-6 with copper-zinc (90 %−10 %) alloy. Because of its highly sensitive performance, this sensor can be an impressive appliance for the identification of organic substances, biological fluids, and samples.

Demodulation of a polarization‐maintaining photonic crystal fiber load sensor with high resolution using a microwave photonic filter

AbstractA new demodulation technique for polarization‐maintaining photonic crystal fiber pressure sensor with high resolution based on a simple photonic microwave filter has been proposed and demonstrated. Unlike the conventional methods that use optical interferometry and optical spectrum analysis, the proposed method adopts microwave photonics technique. The relationship between load and the notch frequency of the filter is studied. By measuring the notch frequency of the filter, the pressure can be determined and the sensing sensitivity is greatly increased. The sensitivity is as high as 15.625 MHz/N which satisfied well with the theoretical simulation.

Design and computational analysis of photonic crystal sensor to detect acoustic signals for underwater applications using finite difference time domain algorithm

In this paper we have designed the photonic crystal sensor for the detection of underwater pressure using finite difference time domain method. By using the photonic crystal with rods in air configuration, this photonic sensor is designed. Designed sensor is investigated for different pressure values and different values of wavelength are obtained. Two structures are designed, but design 2 photonic sensing structure is more preferred than design 1 because of its high sensitivity values. The highest sensitivity obtained is 369.29 nm/RIU i.e. for design 2. Photonic band gap is identified for each sensing structure and is used for the design of this pressure sensor.

Dynamic Temperature Characteristics of Liquid Filled Photonic Crystal Fiber

The dynamic characteristics of high sensitivity temperature sensor are studied by using siphon method to fill the air hole near the core of the hollow photonic crystal fiber with Cargille matching liquid, and the two ends are fused with single-mode fiber in this work. We analyzed the working principle of filled photonic crystal fiber sensor by using the standard coupling mode theory of directional coupler. The coupling process was simulated by COMSOL software. When the photonic crystal fiber filled with 10 mm liquid was scanned by tunable laser, the temperature sensitivity was 7.50 nm /°C, the average temperature response time was 0.317 s, the average release time was 3.732 s, and the temperature variation linearity was 100%. The experimental results show that the liquid filled photonic crystal fiber has the advantages of high temperature sensitivity, fast response time and good linearity.

Magnetic field sensor based on evanescent wave coupling effect of photonic crystal slab microcavity

In this study, a novel magnetic field sensor (MFS) based on 2D photonic crystal slab (2D PCS) microcavity is proposed. Magnetic fluid film (MFF) covers the surface of PCS and is coupled to high-Q microcavity by evanescent field. The slight disturbance of the refractive index of MFF can cause a larger response of the microcavity optical local field. The magnetic field calibration is realized by measuring the output power of W1 waveguide. The finite difference time domain (FDTD) method was used to analyze and optimize the sensing characteristics of MFS. The simulation results show that the PCS magnetic sensor has good linearity and sensitivity. When the MFF with a thickness of L = 0.4 μm completely covers the surface of PCS, the normalized sensitivity of W1 type waveguide-single microcavity coupling sensor structure can reach 2.52/T. Compared with the traditional photonic crystal magnetic sensor, the PCS magnetic sensor structure designed in this paper can adopt the existing MEMS processing technology and is easy to fabricate.

High sensitive triangular photonic crystal fiber sensor design applicable for gas detection

A new triangular photonic crystal fiber with a based microstructure core gas sensor has been proposed for the wavelength range from 1.1μm to 1.7μm. The guiding trait of the proposed structure depends on geometric parameters and wavelength, which are numerically studied by the finite element method. According to the results, the relative sensitivity obtained as high as 75.14% at 1.33μm wavelength. high birefringence and effective area are also obtained by order of 3.75×10-3 and 14.07 μm2 finally, low confinement loss of 1.41×10-2 dB/m is acquired at the same wavelength. The variation of the diameters in the cladding and core region is investigated and the results show that this structure has good stability for manufacturing goals. Since the results show the highest sensitivity at wavelengths around 1.2μm to 1.7μm, which is the absorption line of many gases such as methane (CH4), hydrogen fluoride (HF), ammonia (NH3), this gas sensor can be used for medical and industrial applications.

Simulation design of silver nanoparticle coated photonic crystal fiber sensor based on surface plasmon resonance

Surface Plasmon Resonance (SPR) is the charge density excitation oscillation (surface Plasmon’s, (SP)) caused by the polarized light along with the metal-dielectric interface by agreeing to phase-matching condition between polarized light and SPR. SPR method has unusual advantages like label-free, real-time and high resolutions with less than 10-7 RIU which is not consenting with other sensing methods. Photonic Crystal Fiber (PCF) presents unique features like design elasticity, geometric flexible and extraordinary guiding mechanism which head for better performance contrast conventional optical fibre, Additionally, the presence of air holes gives the possibility to insert multi able materials, that can recognize the interaction of travelling light and materials operatively. Adding the advantages of PCF to the properties of SPR, lead to design very strong and unique devices in different applications. In this paper, the PCF sensor based on SPR technique had been presented. The inner holes of PCF were coated with silver and then filled with air and ethanol. This was achieved theoretically by Finite Element Method (FEM). When the phase-matching condition was achieved at a fixed wavelength, the energy of the core-guided mode is shifted to the plasmon area and a resonant loss peak is observed at this wavelength. The simulated results show that a blue shifting is obtained when the outer air holes of PCF is filling with ethanol while the inner ring is filled with silver nano-particles. The maximum resolution and sensitivity are 5.66*10-4 RIU, 132.3 nm/RIU respectively in the sensing range of air refractive index to ethanol refractive index are obtained. The submitted design could be very useful in many fields like refractive index and temperature sensing applications.

Analysis of GaN-based 2D Photonic Crystal Sensor for Real-time Detection of Alcohols

The present research proposes an extensive assay of photonic band gap (PBG) characteristics for transverse electric field polarization in two-dimensional (2D) photonic crystal (PhC) structures, with a vision to sense different groups of alcohol like methanol, ethanol, propanol, butanol and phenol. The plane wave expansion (PWE) technique is implemented for realization of PBG in two types of lattice configurations such as square lattice and triangular lattice with circular air holes. Various structure parameters like radius of the circular air holes, lattice constant, nature of the background material, arrangement of air holes and period of air holes are meticulously optimized for envisaging a complete band gap. A variety of unpredicted trends are observed in the simulation outcomes, which include a substantial shift in band gap width, band gap size, reflected wavelength, reflected light intensity and transmitted light intensity for different types of alcohols. Also, the effect of air filling fraction on the band gap size has been investigated by selecting different radius of circular air holes. Apart from this, high sensitivity of 1645 nm/RIU and resolution of $$6.07\times {10}^{-5}$$ RIU is attained with the proposed structures, which pave the path for different bio-sensing applications.

Rapid self-assembly preparation of p-nitrophenol-molecular imprinted photonic crystal sensors

To overcome the long period of three-dimension photonic crystal colloidal array preparation, a rapid self-assembly method is proposed. The effect of microspheres diameter and concentration, heating and nitrogen blowing have been also studied. According to the results, when the microspheres suspension concentration is 0.2 wt% and heating temperature of 70 °C, a highly regular 3D face-centered cubic colloidal crystal array structure self-assembles on the gas-liquid interface within 3 min. Then using this method, a p-nitrophenol-molecular (p-NP) imprinted photonic crystal sensor with high selectivity and sensitivity is prepared. The p-NP imprinted sensor presents twice signal intense than the non-imprinted sensor towards the target, and the structural color changes from blue to green. Meanwhile, the sensor responds in 3 min and can be reversible more than 9 times. This rapid self-assembly method provides a suitable way for large-area colloidal photonic crystal preparation with higher efficiency and good repeatability, which has a high value for practical applications.

Analysis of Double Peak Detection in a D-Shaped Photonic Crystal Fiber Plasmonic Sensor

We present a novel D-shaped photonic crystal fiber sensor with double loss peaks based on surface plasmon resonance. The proposed sensor has a lot of better characteristics for refractive index detection compared with single-peak sensor. It is worth noting that the trough of the loss spectrum keeps unchanged as the analyte refractive index increases, which indicates that this sensor is extremely stable. In addition, numerical simulation shows that the average wavelength sensitivity can reach 29,000 nm/RIU and the maximum resolution is as high as 3.45 × 10−5 RIU. Furthermore, the coupling theory between fundamental mode and the surface plasmon polarization (SPP) mode is investigated in this paper. It is found that there is obvious competition between the resonant modes. This study has enlightening significance for us to understand the generation mechanism of polarization-entangled quantum photo source.

Analysis of a photonic crystal temperature sensor based on Z-shaped ring resonator

A 2D photonic crystal (PC) sensor based on optical filter has been designed using a PC ring resonator (PCRR). The sensor used a 2D-PCRR triangular lattice with circular silicon rods placed in air background. We employed a ring resonator with Z-shaped core in the investigated structure, which is designed as temperature sensor and investigated theoretically along with high quality factor, transmission and sensitivity parameters. For sensing analysis, the 2D finite-difference time-domain method and the plane-wave expansion approach have been applied. A temperature variation from 0 to 20 °C causes a defect mode shifting and the channel filter wavelength shift was used as sensing mechanism. Using the number of the functionalized rods N = 36 at the temperature of 5 °C, the quality factor, the temperature sensitivity, the refractive index sensitivity and the detection limit of the studied structure were found to be 57,104, 96 pm/°C, 400 nm/RIU and 6.16 × 10–6 RIU, respectively.

A simple structure of PCF based sensor for sensing sulfur dioxide gas with high sensitivity and better birefringence

Abstract This paper describes a micro-cored photonic crystal fiber-based gas sensor that uses a simple structure and proper analysis has done to detect sulfur dioxide gas. SO2 is a significant air pollutant that may aggravate existing respiratory and cardiovascular diseases. The numerical investigation has been done in a range of wavelengths from 0.9 ​μm to 1.1 ​μm and as usual, the proposed structure is numerically analyzed by using the complete finite element method. A Perfectly Matched Layer (PML) is used to investigate the optical parameters. We tested the performance of the designed PCFs for sensing sulfur dioxide as a gas sample. We designed the core section of the proposed structure with only a circular shape hole to minimize design complexity. The relative sensitivity can be increased by changing the diameter of the air holes in the microstructure core, cladding holes even the thickness of the PML. The proposed sensor's test is carried out on different Pitch values, PML thickness values, core region's hole diameter variations, cladding hole diameter variations. At fixed wavelength of 1 ​μm, the maximum relative sensitivity obtained here is around 70% with a better birefringence value 1.0 ​× ​10−03 and lower confinement loss.

Seven-core photonic crystal fiber temperature sensor

Seven-core photonic crystal fiber temperature sensor

A sulfamethoxazole molecularly imprinted two-dimensional photonic crystal hydrogel sensor.

In this paper, a molecularly imprinted two-dimensional photonic crystal hydrogel sensor (SMZ-MIPCH) for the sensitive and label-free recognition of sulfamethoxazole (SMZ) was prepared. The SMZ-MIPCH sensor response performance was investigated via measuring the diameter of the Debye ring (D). When the SMZ-MIPCH sensor recognized SMZ, the diameter of the Debye ring gradually decreased and the particle spacing (d) of the photonic crystals gradually increased. As the SMZ concentration increased from 0 to 10-4 mol L-1, the diameter decreased by 15.2 mm and the corresponding particle spacing increased by 131 nm. As the diffraction peak wavelength of the sensor gradually red-shifted, the color changed from blue to green and finally to orange-red. A good linear relationship was found between the variation of the particle spacing (Δd) and the value of the logarithm of the SMZ concentration (lg c) in the range from 10-16 mol L-1 to 10-10 mol L-1. The limit of detection of the SMZ-MIPCH sensor is 10-16 mol L-1. In the presence of analogues of SMZ, such as sulfisoxazole, sulfadiazine, and sulfamethazine, the diameter changed only slightly, indicating that the SMZ-MIPCH sensor had specific recognition abilities for SMZ. The SMZ-MIPCH sensor has the advantages of high sensitivity, specific recognition, and naked eye detection, and it can be used for the detection of SMZ in water samples.

A 1D binary photonic crystal sensor for detecting fat concentrations in commercial milk.

Our goal in this study is to design an efficient sensor to detect the fat volume in commercial milk. We used a one-dimensional binary photonic crystal to design the sensor and the Transfer Matrix Method to study theoretically its optical response as the refractive index of milk samples changes due to the change in fat concentration. We found that the proposed sensor is efficient in sensing the fat concentration in milk. The optimum defect layer thickness is found to be 1.20 μm and the sensitivity of the sensor improved as the angle of incidence of radiation increased up to 60°. Besides, we proposed an empirical formula that can be used to estimate the fat concentration in milk. The efficiency of our sensor is based on the quick response of the sensor to the changes in the fat concentration in milk. The output signal of the sensor would be processed in a signal processing unit that will give an accurate estimation of the fat concentration in milk. The sensor is easy to fabricate, cost-effective, and user-friendly.