Numerical analysis of effective refractive index bio-sensor based on graphene-embedded slot-based dual-micro-ring resonator

Abstract

<jats:p> We propose a novel bio-sensor structure composed of slot dual-micro-ring resonators and mono-layer graphene. Based on the electromagnetically induced transparency (EIT)-like phenomenon and the light-absorption characteristics of graphene, we present a theoretical analysis of transmission by using the coupled mode theory and Kubo formula. The results demonstrate the EIT-like spectrum with asymmetric line profile. The mode-field distributions of transmission spectrum are obtained from 3D simulations based on finite-difference time-domain (FDTD) method. Our bio-sensor exhibits theoretical sensitivity of 330 nm/RIU, a minimum detection limit of [Formula: see text] RIU, the maximum extinction ratio of 4.4 dB, the quality factor of [Formula: see text] and a compact structure of [Formula: see text]. Finally, the bio-sensor’s performance is simulated for glucose solution. Our proposed design provides a promising candidate for on-chip integration with other silicon photonic element. </jats:p>

Numerical analysis of a highly sensitive SOI MRR refractive index sensor with performance enhancement using graphene and gold

“…The coupling between the ring resonator and the excitation signal ( ) provided at the input port are related by equation (2) [ 13 , 54 , 55 ]: and are the normalized amplitudes of complex modes. The couplers' transmission coefficient ( t ) and coupling coefficient ( k ) rely on one another based on equation (3) [ 54 ]: …”

“…FWHM plays a crucial role in establishing the quality of a sensor, as a lower FWHM allows us to observe a more distinct resonance shift. Refractive index sensors are also well suited for the development of numerous sensor categories for evaluating biosensing, including blood group detection [ [13] , [14] , [15] , [16] ], hemoglobin concentration detection [ 17 ], and cancer cell detection [ 18 ].…”

“…As a result of earlier research, additional attempts have been made to improve the performance of SOI MRRs by introducing graphene, a two-dimensional material with outstanding characteristics. High-performance optical modulators and biochemical sensors can be made from graphene, which can also impact the transmission spectrum [ 13 ]. Various wavelengths, including the visible and near-infrared, show substantial optical absorption in graphene.…”