Small Changes In Refractive Index Research Articles

Machine Learning Approach to Data Processing of TFBG-Assisted SPR Sensors

Fiber optic sensors are applied in industry, remote sensing, environmental monitoring and healthcare. A special place is occupied by tilted fiber Bragg gratings, which can significantly expand the capabilities provided by standard Bragg sensors. But these gratings have complex spectral responses, therefore, data processing becomes a critical task for achieving maximum performance. In this paper, machine learning methods for processing spectral data of a plasmonic fiber sensor based on a tilted fiber Bragg grating were applied for the first time for the measurement of small refractive index changes. The responses of two similar but not identical sensors were measured in two independent experiments. The model trained on the data of the first sensor was used to analyze data obtained with another sensor. The best resolution achieved in our experiments was <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$9 \times {10^{ - 6}}$</tex-math></inline-formula> RIU.

Non-Volatile Reconfigurable Silicon Photonics Based on Phase-Change Materials

The traditional ways of tuning a silicon photonic network are mainly based on the thermo-optic effect or the free carrier dispersion. The drawbacks of these methods are the volatile nature and the extremely small change in the complex refractive index (Δn<0.001). In order to achieve low energy consumption and smaller footprint for applications such as photonic memories, optical computing, programmable gate array, and optical neural network, it is essential that the two optical states of the system exhibit high optical contrast and remain non-volatile. Phase change materials (PCMs) such as Ge <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Sb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> Te <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> provide an excellent solution, thanks to the drastic contrast in refractive index between two states which can be switched reversibly and in a non-volatile fashion. Here, we review the recent progress in the field of non-volatile reconfigurable silicon photonics based on PCMs. We start with a general introduction to the material properties of PCMs that have been exploited in integrated photonics and discuss their operating wavelengths. The various photonic switches that are built upon these PCMs are reviewed. Lastly, we review the recent applications of PCM-based photonic integrated circuits and discuss the potential future directions of this field.

Toward Confocal Chromatic Sensing in Nuclear Reactors: In Situ Optical Refractive Index Measurements of Bulk Glass

To measure fuel rod swelling in a nuclear research reactor, our research has focused on the development of an optical confocal chromatic sensor, allowing contactless measurements of radial changes in fuel rods. This sensor must be able to operate in the harsh and hot environment of a reactor, especially under high neutron fluences up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{19}~{n}_{\mathrm{ fast}}/\text {cm}^{2}$ </tex-math></inline-formula> and gamma doses of a few GGy. When exposed to such radiation levels, the properties of bulk optical glasses are known to be affected by two main phenomena: radiation-induced attenuation (RIA) and radiation-induced refractive index change (RIRIC). With the objective of testing glasses as candidates for a future confocal chromatic sensor, we created a dedicated setup for the online monitoring of the glasses’ RIRIC in the core reactor with a measurement principle relying on interferometry. Since not only the refractive index (RI) but also the length of the samples changes under neutron radiation through compaction, we measured the variation of the optical path (OP) ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$nL$ </tex-math></inline-formula> ). To assess the performance of our setup, preliminary in-lab tests were performed to evaluate the feasibility of measuring the small RI changes caused by external temperature changes. Due to this study, we were able to obtain data that were not yet available in the literature regarding the temperature-induced RI variation of several bulk glasses, including radiation-hardened glasses, up to 350 °C. This information is crucial for the targeted application, as the confocal chromatic sensor will have to operate at such elevated temperatures.

Ultrasensitive Detection of Heavy Metal Ions with Scalable Singular Phase Thin Film Optical Coatings

AbstractIdentification of spectroscopically silent heavy‐metal ions in environmental and bio‐analytical samples has gained immense importance. Lowering the limit of detection of these ions at low concentrations is crucial for biomedicine and food safety applications. Optical chemical sensors have shown great potential in improving the sensing solutions for heavy‐metal ions because of their fast and label‐free detection capabilities. However, achieving high sensitivity without compromising on scalability and simplicity is challenging. Here, we experimentally demonstrate the detection of heavy metal ions at ultralow concentrations using lithography‐free scalable thin film optical coatings that show singular behavior of phase of light at the point‐of‐darkness. Since the phase‐sensitive optical techniques have shown superior sensitivity over traditional sensing techniques based on spectroscopy, we use this extreme phase change to detect zinc ions concentration down to femtomolar. In particular, it allows us to monitor very small changes in refractive index due to the real‐time binding of zinc ions on a poly (lactic‐co‐glycolic acid) functionalized sensor surface. This cost‐effective extreme sensitivity sensing platform can be used for the label‐free detection of various heavy metal ions by properly functionalizing the sensor surface.

Simple quad-band terahertz metamaterial absorber based on high-order plasmon resonance for sensing applications

We present a simple quad-band terahertz (THz) metamaterial absorber for perfect absorption. Unlike most reported absorbers, the proposed structure achieves perfect absorption based on high-order plasmon resonance, with the absorptivity of the first three peaks all >99.4 % . First, the resonance absorption mechanism of the absorber involving fundamental resonance mode and high-order resonance mode is analyzed in detail. Next, the sensing performance is also studied by changing the ambient refractive index, the numerical results show that the designed multiband metamaterial absorber is very sensitive to small changes in refractive index, and appears highly sensitive in its sensing performance. In particular, figure of merit of the last absorption peak reaches 26.6, which is far superior to most multiband metamaterial absorbers operating in the THz regime. The proposed simple structure not only greatly simplifies the fabrication, but also is insensitive to the polarization of incident waves. The results show that the quad-band metamaterial absorber has potential applications in sensing, imaging, detection, and other fields.

Maximizing spectral sensitivity of plasmonic photonic crystal fiber sensor

We propose a novel design for a plasmonic photonic crystal fiber (PCF) sensor. Our design includes a metal film incorporated within the PCF structure. Compared to previously discussed sensing configurations, the metal surface does not come in direct contact with the sample being tested in our design. The metal film serves to provide absorption due to the excitation of surface plasmon-polaritons (SPP). This absorption is enhanced when a PCF-guided mode resonantly couples to the SPP, or in other words when phase matching between the mode and the SPP is satisfied. We consider a configuration where a hollow PCF core is filled with a liquid sample, while the metal surfaces are kept tens of microns away within the PCF cladding. Our sensor detects small changes in the sample's refractive index, over a broad wavelength range, by taking advantage of the refractive index sensitivity of the resonance/phase-matching condition. We model the sensor and characterize its performance by using the COMSOL environment based on the finite element method. We evaluate and compare three elements: gold, silver, and copper, in order to increase the absorption at particular wavelengths. We also vary the thickness of the metal layer and optimize it to enhance the sensitivity. The results show a performance that exceeds a minimal sensor resolution over an ultra-broad spectral range while maintaining a reasonable amplitude sensitivity.

Measuring the refractive index of a methanol - water mixture according to the wavelength

The refractive index of the methanol-water mixture depending on the wavelength at different concentrations was determined by our experimental method using a Michelson interferometer system. A comparative study of Gladstone-Dale, Arago–Biot and Newton relations for predicting the refractive index of a liquid has been carried out to test their validity for the methanol-water mixture with the different concentrations 30%, 40%, 50%, 60%, 80%, and 100%. The comparison shows the good agreement between our experimental results and the results in the expressions studied over the wavelength range approximately from 450 to 850 nm. Full Text: PDF ReferencesS. Sharma, P.B. Patel, R.S. Patel, "Density and Comparative Refractive Index Study on Mixing Properties of Binary Liquid Mixtures of Eucalyptol with Hydrocarbons at 303.15, 308.15 and 313.15 K", E-Journal of Chemistry 4(3), 343 (2007). CrossRef A. Gayathri, T. Venugopal, R. Padmanaban, K. Venkatramanan, R. Vijayalakshmi, "A comparative study of experimental and theoretical refractive index of binary liquid mixtures using mathematical methods", IOP Conf. Series: Materials Science and Engineering 390, 012116 (2018). CrossRef A. Jahan, M.A. Alam, M.A.R. Khan, S. Akhtar, "Refractive Indices for the Binary Mixtures of N, N-Dimethylformamide with 2-Butanol and 2-Pentanol at Temperatures 303.15 K, 313.15 K, and 323.15 K", American Journal of Physical Chemistry 7(4), 55 (2018). CrossRef N. An, B. Zhuang, M. Li, Y. Lu, Z. Wang, "Combined Theoretical and Experimental Study of Refractive Indices of Water–Acetonitrile–Salt Systems", J. Phys. Chem. B 119(33), 10701 (2015). CrossRef M. Upadhyay, S.U. Lego, "Refractive Index of Acetone-Water mixture at different concentrations", American International Journal of Research in Science, Technology, Engineering &amp; Mathematics 20(1), 77 (2017). CrossRef T.H. Barnes, K.Matsumoto, T. Eiju, K. Matsuda, N. Ooyama, "Grating interferometer with extremely high stability, suitable for measuring small refractive index changes", Appl. Opt. 30, 745 (1991). CrossRef B. W. Grange, W. H. Stevenson, R. Viskanta, "Refractive index of liquid solutions at low temperatures: an accurate measurement", Applied Optics 15(4), 858 (1976). CrossRef P. Hlubina, "White-light spectral interferometry with the uncompensated Michelson interferometer and the group refractive index dispersion in fused silica", Optics Communications 193(1-6), 1 (2001). CrossRef P. Hlubina, W. Urbanczyk, "Dispersion of the group birefringence of a calcite crystal measured by white-light spectral interferometry", Meas. Sci. Technol. 16(6), 1267 (2005). CrossRef P. Hlubina, D. Ciprian, L. Knyblová, "Direct measurement of dispersion of the group refractive indices of quartz crystal by white-light spectral interferometry", Optics Communications 269(1), 8 (2007). CrossRef S. R. Kachiraju, D. A. Gregory, "Determining the refractive index of liquids using a modified Michelson interferometer", Optics &amp; Laser Technology 44(8), 2361 (2012). CrossRef F. Gladstone, D. Dale, "XXXVI. On the influence of temperature on the refraction of light", Philos. Trans. R. Soc. 148, 887 (1858). CrossRef D.F.J. Arago, J.B. Biot, Mem. Acad. Fr. 15, 7 (1806). CrossRef Kurtz S S and Ward A L J, "The refractivity intercept and the specific refraction equation of Newton. I. development of the refractivity intercept and comparison with specific refraction equations", Franklin Inst. 222, 563-592 (1936). CrossRef K. Moutzouris, M. Papamichael, S. C. Betsis, I. Stavrakas, G. Hloupis, D. Triantis, "Refractive, dispersive and thermo-optic properties of twelve organic solvents in the visible and near-infrared", Appl. Phys. B 116, 617 (2013). CrossRef S. Kedenburg, M. Vieweg, T. Gissibl, H. Giessen, "Linear refractive index and absorption measurements of nonlinear optical liquids in the visible and near-infrared spectral region", Opt. Mater. Express 2(11), 1588 (2012). CrossRef

Electrically Tunable Singular Phase and Goos-Hänchen Shifts in Phase-Change-Material-Based Thin-Film Coatings as Optical Absorbers.

The change of the phase of light under the evolution of a nanomaterial with time is a promising new research direction. A phenomenon directly related to the sudden phase change of light is the Goos-Hänchen(G-H) shift, which describes the lateral beam displacement of the reflected light from the interface of two media when the angles of incidence are close to the total internal reflection angle or Brewster angle. Here, an innovative design of lithography-free nanophotonic cavities to realize electrically tunable G-H shifts at the singular phase of light in the visible wavelengths is reported. Reversible electrical tuning of phase and G-H shifts is experimentally demonstrated using a microheater integrated optical cavity consisting of a dielectric film on an absorbing substrate through a Joule heating mechanism. In particular, an enhanced G-H shift of 110 times of the operating wavelength at the Brewster angle of the thin-film cavity is reported. More importantly, electrically tunable G-H shifts are demonstrated by exploiting the significant tunable phase change that occurs at the Brewster angles, due to the small temperature-induced refractive index changes of the dielectric film. Realizing efficient electrically tunable G-H shifts with miniaturized heaters will extend the research scope of the G-H shift phenomenon and its applications.

Irregular hexagonal core based surface plasmon resonance sensor in near-infrared region

In this work, a highly sensitive yet simple hexagonal photonic crystal fiber (PCF) based surface plasmon resonance (SPR) refractive index (RI) sensor is proposed. The proposed structure consists of twelve purely circular air-holes to render the fabrication process easily realizable. For the feasibility of operation, the target analyte, and the plasmonic material, Indium Tin Oxide (ITO) are employed around the outer surface of the sensor. The performance of the sensor is numerically analyzed using the full-vectorial finite element method (FEM) for different fiber geometric parameters and RI variations. A step-by-step design procedure has been followed starting from the regular hexagonal lattice PCF structure. The optimal sensor performance is obtained by tuning the geometric parameters over the relevant numeric range. It is shown that the proposed sensor achieves a maximum wavelength sensitivity of 37000 nm/RIU and a maximum amplitude sensitivity of 407.285 RIU-1for a dielectric RI range from 1.33 to 1.40 in the near-infrared wavelength regime (1470 nm − 2220 nm). Apart from this, to ensure high detection accuracy of small refractive index (RI) changes, the sensor achieves the highest wavelength resolution and amplitude resolution of 2.70×10-6 RIU and 2.46×10-5RIU-1, respectively, along with the highest Figure of Merit of 217.65 RIU-1. Hence, the proposed PCF-SPR sensor can potentially be used to detect unknown refractive indices for various applications including biosensing.

Phase-interrogated surface plasmon resonance sensor based on laser feedback interferometry

This work reports a phase-interrogated surface plasmon resonance sensor based on a laser feedback interferometer to detect a small refractive index change. The laser feedback interferometer technique is introduced to demonstrate the sensing technique's performance, which offers several inherent advantages, such as compact, optically self-aligned, and high accuracy measurement. Moreover, this technique doubles the interrogating light beam propagation to the solution under the test, leading to an improvement of intrinsic sensitivity measurement up to two-fold. The proposed technique was characterized, and the performance was compared to another phase-interrogated surface plasmon resonance (SPR) based on the Mach-Zehnder interferometer. Laser feedback interferometer SPR has shown significant improvement to the performance parameter under test, namely sensitivity, drift, repeatability, and resolution.

Ultracompact gas-sensor based on a 2D photonic crystal waveguide incorporating with tapered microcavity

In this study, a new ultra compact gas-sensor, based on a 2D photonic crystal waveguide incorporating with tapered microcavity, is designed to detect small refractive index changes. The refractive index (RI) sensor is formed by a point-defect resonant cavity in the sandwiched waveguide on Si slab with triangular lattice. The properties of the sensor are simulated by using the plane wave expansion (PWE) method and the finite-difference time-domain (FDTD) algorithm. The transmission spectra of the sensor with different ambient refractive indices ranging from n = 1.0 to n = 1.01 are calculated. The calculation results show that a change in ambient refractive index of Δn=1×10−4is apparent. The proposed sensor achieves a sensitivity (Δλ/Δn) of 523.2 nm/RIU. It was found that the resonance wavelength is a linear function of the refractive index in under study range. The sensor is appropriate for detecting homogeneous media.

Surface plasmon based fiber optic refractive index sensor

This paper has proposed a surface plasmon resonance-based photonic crystal fiber (PCF) sensor to detect even a small change in refractive index (RI) values of analytes. The impact on sensor performance by Bezier polygon core structure of the PCF and gold coating in an air hole have been carried out. The sensor resonance wavelength and the respective confinement loss are analyzed for various Bezier polygon parameters and for various gold coating thicknesses. Also, a comparison between gold filling and gold coating in an air hole of PCF have been undertaken to show the superiority of the gold coating in sensor performance. The promising sensor performance has been noted down above the analyte RI of about 1.3 with an upright sensitivity of about 7000 nm/RIU. This type of sensor is of great interest in medical and industrial applications.

Photonic Crystal Fiber Based Biosensor for Pseudomonas Bacteria Detection: A Simulation Study

The detection of microorganisms like Pseudomonas are very important as they trigger an infection in human blood, lungs, and different parts of the body causing various ailments. In this paper, a surface plasmon resonance (SPR) biosensor based on photonic crystal fiber (PCF) has been proposed to detect the presence of Pseudomonas bacteria with attractive performance characteristics. The sensor is designed using a simple circular lattice of PCF, coated with a thin chemically stable gold layer. The performance investigation of the sensor is numerically carried out by using a finite element (FE) based simulation tool where the highest wavelength and amplitude sensitivity are found as 20,000 nm/RIU and 1380 RIU <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> , respectively. The sensor shows an excellent spectral resolution of the highest value of 5.26×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> RIU, ensuring the capability of identifying a very small change in analyte refractive index (RI) within the range of 1.33 to 1.42. The performance investigation is also carried out altering the diameter of air holes, pitch, and gold layer thickness to explore the variation in phase matching conditions due to the change in structural parameters. As the sensor is adept at detecting the sample with high sensitivity and sensing resolution, the proposed sensor can be highly efficient in detecting Pseudomonas bacteria as well as other organic compounds, and biological analytes.

Numerical design of three-dimensional gradient refractive index structures for beam shaping.

A numerical design method is demonstrated for gradient refractive index (GRIN) beam shapers embedded in a medium. The three-dimensional refractive index profile Δn(x, y, z) gradually changes the spatial characteristics of a beam during propagation. Diffraction effects such as beam expansion are controlled and compensated by the refractive index profile, resulting in efficient field transformations with no coherent artifacts. The solution is found using phase retrieval and a paraxial scalar wave beam propagation model. An example design is shown in which small changes in refractive index (Δn < 10-3) are used to transform a beam over a device length of 10 mm.

Nanophotonic Device Based on Fano Resonance in Engineered Slot Waveguide for Optical Detection of Viral Infections

A nanophotonic biosensing platform based on an engineered slot waveguide is proposed. The proposed device is based on Fano resonance which consists of a periodic arrangement of two rows of nano-disks and rectangular grating. The periodically arranged nano-disk structure in the form of engineered slot waveguide provides enhanced light-matter interaction and easy accommodation of bio-samples. The surface morphology of (3-Aminopropyl) trimethoxysilane (APTMS) as a functionalized layer on the silicon surface is experimentally analyzed. The proposed sensor device can detect very small refractive index change of 0.0008. Based on refractive index sensing, the device numerically exhibits a high sensitivity of 1463 nm/RIU for some viral infections including hepatitis B the with a Figure of Merit (FOM) of 471 for refractive index change of 0.02. The limit of detection for the proposed device is 1.02 $\times10^{-3}$ RIU (Refractive Index Unit). The proposed scheme with Fano like resonance spectrum carries a great potential for on-chip and off-chip nanoscale optical devices and sensors.

Low‐Index‐Contrast Dielectric Lattices on Metal for Refractometric Sensing

AbstractThis article reports refractometric sensing using two optical resonances of different types supported by TiO2 nanopillar arrays on a gold film, which can be exposed to aqueous or organic environments. One lattice resonance, with enhanced electric fields extending into the surrounding environment, can maintain a quality factor Q &gt; 200 when the bulk refractive index of the surrounding environment varies in a large range from 1.33 to 1.58. This lattice resonance exhibits not only sharp transitions of reflected light intensity but also rapid phase changes. The other resonance is of plasmonic nature with electric fields localized on the metal surface. Small changes in the bulk refractive index or the adsorbate layer (thickness and index) can be detected, with sensitivity comparable to that of plasmonic counterparts. The present hybrid metal–dielectric platform is promising for applications requiring dielectric instead of metallic sensing surfaces.

Electro-optically tunable laser with ultra-low tuning power dissipation and nanosecond-order wavelength switching for coherent networks

The huge amount of data traffic behind the rapid growth of cloud computing is putting pressure on the operation of mobile fronthauls and data center networks so there is a need to improve their power consumption and latency. We developed an electro-optically tunable laser diode employing a tunable filter that is practically tuned even with small refractive index change of the electro-optic effect. The laser shows a small tuning power dissipation of less than 10 mW for a practical tuning range of over 35 nm with a linewidth of about 350 kHz. We also achieved high-speed optical switching of less than 50 ns for 100 Gb/s coherent signals. In addition to its application in optical communications, the electro-optically tunable laser diode is also beneficial to laser sensing applications because its higher tuning speed increases the time resolution of the sensing system. Furthermore, a narrow linewidth, conventionally difficult to reconcile with high-speed tuning, can also enable a longer sensing distance and/or a higher signal-to-noise ratio when using coherent detection. Our result shows that we can use the electro-optic effect to overcome the limitations of conventional tunable laser diodes and drastically change optical communications and laser sensing systems.

Surface plasmonic resonance based five layered structure-biosensor for sugar level measurement in human

In this paper, five layered Surface Plasmon Resonance (SPR) based optical biosensor has been designed for the detection of sugar concentration level in human body. For accuracy and sensitivity measurement here metamaterial and silica has been considered in the third layer for two different structure, respectively. Considering the advantages of exceptional properties of metamaterials, this is highly sensitive and label-free biosensor that has been simulated and analyzed. And a comparative study has been done by considering angle modulation method for better performance and structural design in SPR based biosensor. An Analysis and Simulation has been done for urine sample with various sugar concentration, present in normal person (0–15 mg/dL), and with diabetic person with 0.625, 1.25, 2.5, 5, and 10 g/dL. From literature surveys it is found that for variation in sugar concentration in urine sample, will have different refractive indices, respectively. Light source of 1632.8 nm is used for excitation of five-layer SPR based biosensor. After simulation it has been observed that by using metamaterial, it provides a much sharper reflectance dip and can significantly improve biosensor’s sensitivity. Comparative study has been made with two above mentioned structural design. As a result metamaterial layer-based structure is found to be highly sensitive in comparison with Silica-based biosensor for small changes in refractive index. It is seen that the small change in refractive index makes it highly sensitive. It is also observed that, for the small variation in refractive index there is a distinct shift in reflectivity in metamaterial based SPR biosensor in compare to the silica-based biosensor. This design will be applicable in measurement of sugar level in diabetic and normal person accurately.

Non-Equidistant Arrangement in All-Dielectric Quadrumers and Mirror-Symmetric One-Dimensional Photonic Crystals Hybridstructure for Self-Referenced Sensing Scheme

All-dielectric nanostructures have attracted attention for highly efficient light manipulation. Higher Q-factor Fano resonance can be excited due to the rich phenomenology of optical modes supported by high-index dielectric materials with low intrinsic material loss, including both electric and magnetic multipolar Mie resonances. So far, there have been few studies done on the sensing with Fano-resonant all-dielectric resonator nanostructures. Here, an all-dielectric self-referenced optical sensor is numerically demonstrated based on Si quadrumers and mirror-symmetric 1-D photonic crystals (1DPCs) hybridstructure, operating at the infrared wavelength range with higher sensing performance and much more stable reference signal. Magnetic Fano resonance and Fabry-Perot resonance were combined into such a hybridstructure for the first time. The influences of the gap distance, including Δx and Δy, on the coupling effects between the Si nanodimers along the polarization direction and the 1DPCs are systematically discussed. The sensing performance has been numerically investigated in different analytes with the sensitivity and figure of merit (FOM) of 760 nm/RIU and 1515 RIU <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> respectively, which paves the way to be a much more sensitive detection of small refractive index changes in an unstable environment and suggests potential applications in biological and chemical sensing.

Graphene ultraviolet ultrahigh-Q perfect absorption for nanoscale optical sensing.

We propose an ultraviolet perfect ultranarrow band absorber by coating a dielectric grating on the monolayer graphene-dielectric-metal structure. The absorber presents an ultranarrow Fano lineshape with quality (Q) factor of 70 and a nearly perfect absorption of over 99.9% in the ultraviolet region, which is ascribed to the near field coupling of the optical dissipation of graphene and guide mode resonance of the dielectric grating. Structure parameters to the influence of the performance are investigated. The structure exhibits the high optical sensitivity (S = 150 nm/RIU, S* = 48/RIU) and figure of merit (FOM = 50, FOM* = 25374) and can also be used to detect the nanoscale analyte layer of sub-nanometer thickness, suggesting great potential applications in ultra-compact efficient biosensors for a much more sensitive detection of small refractive index changes.