Compact Slot Microring Resonator for Sensitive and Label-Free Optical Sensing

Abstract

A novel all-pass slot microring resonator (SMRR), intended for label-free optical biosensing based on silicon-on-insulator platforms, is proposed. The sensor consists of a bent asymmetric directional coupler and an asymmetric-slot microring waveguide. The appropriate slot width of 140 nm is identified by the three-dimensional finite-difference time-domain (3D-FDTD) method for better light–matter interaction in applications. According to numerical calculations, the SMRR sensor with a footprint of 10 µm × 10 µm has a concentration sensitivity of 725.71 pm/% for sodium chloride (NaCl) solutions. The corresponding refractive index sensitivity is 403 nm/RIU (refractive index unit), which is approximately six times greater than that of traditional microring resonator sensors. A low detection limit of 0.129% is also achieved. This SMRR is an excellent candidate for label-free optical biosensors due to its compact structure and excellent sensing capability.

Eight-channel SiNx microring-resonator based photonic biosensor for label-free fluid analysis in the optical C-band *

“…A Q-factor of 1.2•10 5 is achieved. In comparison to similar studies reviewed in [14], [15] and [16], maximum Q-factors of 7.0•10 4 were achieved. To estimate the resolution and sensitivity of the sensors, the PIC was integrated with the developed microfluidics.…”

“…According to (4) this results in a system LOD of 2.3•10 -5 . On-chip systems with similar microring-resonator based configurations [14,15,16,17,18] presented a system LOD in the range of 10 -4 ~ 10 -6 . The results of this work are thus comparable.…”

Silicon-Based On-Chip Tunable High-Q-Factor and Low-Power Fano Resonators with Graphene Nanoheaters

“…In the past decade, silicon photonic integrated circuits (PICs) have been regarded as one of the most promising platforms for realizing high-performance and multifunctional on-chip photonic devices. Microring resonators (MRRs), as one of the most fundamental components in silicon PICs, are widely used in the area of modulation [ 1 , 2 ], filters [ 3 ] and sensing [ 4 , 5 ]. As silicon PICs are scaled up, high-performance MRRs usually require a high Q-factor, low energy consumption, and a large tunable range.…”

Highly Sensitive Liquid M-Z Waveguide Sensor Based on Polymer Suspended Slot Waveguide Structure

“…In 2022, Bingyao Shi et al proposed a novel all-pass slot microring resonator (SMRR). The corresponding refractive index sensitivity is 403 nm/RIU, which is approximately six times greater than that of traditional microring resonator sensors [ 13 ]. Regarding the organic materials, polymers have been proven to be potential complementary candidates for inorganic PICs [ 14 , 15 ], they have found a wide utilization in the detection field due to their modifiability and structural designability [ 16 ].…”

“…Regarding the organic materials, polymers have been proven to be potential complementary candidates for inorganic PICs [ 14 , 15 ], they have found a wide utilization in the detection field due to their modifiability and structural designability [ 16 ]. The tunable properties of the polymer give the design and fabrication of the photonic devices much more flexibility [ 13 ]. Moreover, biocompatibility is another important and unique feature of polymers.…”