Hybrid plasmonic slot waveguide with a metallic grating for on-chip biosensing applications

Abstract

Designing reliable and compact integrated biosensors with high sensitivity is crucial for lab-on-a-chip applications. We present a bandpass optical filter, as a label-free biosensor, based on a hybrid slot waveguide on the silicon-on-insulator platform. The designed hybrid waveguide consists of a narrow silicon strip, a gap, and a metallic Bragg grating with a phase-shifted cavity. The hybrid waveguide is coupled to a conventional silicon strip waveguide with a taper. The effect of geometrical parameters on the performance of the filter is investigated by 3D finite-difference time-domain simulations. The proposed hybrid waveguide has potential for sensing applications since the optical field is pulled into the gap and outside of the silicon core, thus increasing the modal overlap with the sensing region. This biosensor offers a sensitivity of 270 nm/RIU, while it only occupies a compact footprint of 1.03 µ m × 17.6 µ m .

Temperature tunable Bragg transmission multichannel filters made of two quarter-wave stacks separated by defect layers

“…By inserting only one quarter-wave silica defect layer, we obtained a narrow-band transmission filter in the infrared region within the photonic bandgap of the PC structure. The transmission spectrum can be obtained by TMM [6], as described in equation (1):…”

“…The applications of subwavelength gratings in Si photonics and in high-speed communication are reviewed extensively [4,5]. and n recent times, people have utilized bandpass filters as biosensors, with high sensitivity which have a tremendous lab on chip applications [6]. In the current study, we have investigated the performance of the Bragg Grating, The Bragg grating consists of periodic layered media (1-Dimensional photonic bandgap crystal) comprising alternate stacks of optically transparent substrates with different indices of refraction.…”

Tunable Filters Based on Fano Resonance Using Asymmetric Moving Resonators in a Single Loop System

“…Numerous filters based on waveguide systems have been proposed and manufactured to control and select several frequencies. Photonic waveguides system can be considered as one of the most recent photonic technologies because of its extraordinary photonic properties for a set of applications [1][2][3][4][5][6][7]. The photonic waveguide structures have attracted important attention by the scientific community due to their ability to guide and confine the electromagnetic waves [8].…”