Research On Optical Surface Wave Refractive Index Sensor Based On New Two-dimensional Materials

In this paper,we propose a new two-dimensional material,alumina zeolite nanoplatelets（also known as analite）,for surface plasmon resonance（SPR）sensors to improve sensitivity.As the latest new two-dimensional（2D）material with a naturally occurring van der Waals heterostructure,azolite has a unique advantage over artificially stacked heterostructures.In this structure,aluminate is covered on the surface of the 50nm silver film,so that the SPR sensitivity is related to the thickness of the aluminate coating.Theoretically,a sensitivity of up to 190°/RIU has been obtained,which is a 62%increase in sensitivity compared to traditional SPR biosensors.In addition,considering another black phosphorus film,and further improving the sensitivity of the analite-black phosphorus structure,based on the excellent performance of black phosphorus,the sensitivity of this SPR sensor can theoretically reach 260°/RIU,which is in contrast to traditional surface plasma Compared with the resonance sensor,the sensitivity is improved by 124%,which is enough to show that the sensor of this structure has a large application field.Bloch surface wave（BSW）sensors are considered an ideal alternative to conventional surface plasmon resonance（SPR）sensors.In this study,a high-performance refractive index sensor based on the BSW resonance in a truncated one-dimensional photonic crystal（1DPC）using transition metal sulfide（TMDC）has been theoretically demonstrated.The effects of four different two-dimensional material TMDCs nanosheets on the sensor were studied,thereby realizing the latest technology sensitivity of wavelength query.Specifically,for Mo Se₂,WSe₂,Mo S₂,and WS₂nanosheets,the measured figure of merit（FOM）was 732.1/RIU,733.0/RIU,730.5/RIU,700.7/RIU,respectively.To our knowledge,this is the best performance achieved to date compared to existing BSW and SPR sensors.In addition,the effects of the 1DPC cycle and the number of TMDC layers are also discussed in detail.Moreover,at the interface of TiO₂ and TMDCs,it was found that the electric strength was increased by nearly 7 times compared to the initial strength,which also caused the evanescent depth in the sensing medium to increase.We are very positive that the high-sensitivity sensors proposed in this work can be applied to the fields of biological and chemical sensing.