Research On Refractive Index Sensors Based On Slotted Photonic Crystal Nanobeam Cavities

With the development of science and technology,in the field of optoelectronic technology,basic materials and structures are no longer meeting the needs of social development.Photonic Crystal Nanobeam Cavity(PCNC)has attracted considerable research because of its small size,easy storage of energy,high quality factor and small mode volume.It is widely used in many fields,including detectors,filters,modulators,low-threshold lasers,optical storage,and refractive index sensors.In order to build and develop new types of refractive index sensors with excellent sensing performances and to provide the theoretical basis and guiding principles for the practical fabricated refractive index sensors,based on the previous researches,two novel slotted PCNCs are proposed and two sensors are designed based on these two cavities in this paper.By using the numerical simulation methods,the sensing performances of these sensors are studied.The main research contents and conclusions of this paper are as follows:1)A novel slotted H-shaped PCNC is designed and proposed.The band structure of the slotted H-shaped photonic crystal is firstly analyzed using the plane wave expansion method.By using the three-dimensional finite difference time domain method,the optical properties of the slotted H-shaped PCNC,such as quality factor and mode volume,under different structural parameters are investigated.Then the sensing performance of the slotted H-shaped PCNC-based sensor is studied.The results show that the quality factor of the refractive index sensor is 2×10~6,the mode volume is 0.035(?/n)~3,and the sensitivity is 704.17 nm/RIU.2)A novel slotted fishbone-like PCNC is designed and proposed.The band structure is also analyzed using the plane wave expansion method.The optical properties of the slotted fishbone-like PCNC,such as quality factor and mode volume,under different structural parameters are investigated by using the three-dimensional finite difference time domain method.Finally,the sensing performance of the slotted fishbone-like PCNC-based sensor is studied.The results show that the slotted fishbone-like PCNC-based sensor has a quality factor of 3.5×10~6 and a mode volume of 0.0216(?/n)~3,and a sensitivity of 514.75 nm/RIU.