An Integrated-Plasmonic Chip of Bragg Reflection and Mach-Zehnder Interference Based on Metal-Insulator-Metal Waveguide

Abstract

In this paper, a Bragg reflector is proposed by placing periodic metallic gratings in the center of a metal-insulator-metal (MIM) waveguide. According to the effective refractive index modulation caused by different waveguide widths in a period, a reflection channel with a large bandwidth is firstly achieved. Besides, the Mach-Zehnder interference (MZI) effect arises by shifting the gratings away from the waveguide center. Owing to different optical paths with unequal indices on both sides of the grating, a narrow MZI band gap will be obtained. It is interesting to find out that the Bragg reflector and Mach-Zehnder interferometer are immune to each other, and their wavelengths can be manipulated by the period and the grating length, respectively. Additionally, we can obtain three MZI channels and one Bragg reflection channel by integrating three different gratings into a large period. The performances are investigated by finite-difference time-domain (FDTD) simulations. In the index range of 1.33–1.36, the maximum sensitivity for the structure is as high as 1 500 nm/RIU, and it is believed that this proposed structure can find widely applications in the chip-scale optical communication and sensing areas.

Design and analysis of high performance 1×N optical wavelength demultiplexers based on MIM waveguide with polygon resonators

“…Band-pass and band-stop filtering performance determine the quality of the applications (Cui et al 2023;Janfaza et al 2019;Korani et al 2023;Ebadi et al 2020;Pinton et al 2018;Mao et al 2017). There are many waveguide-based studies such as Mach-Zehnder interferometers (Swarnakar et al 2021;Yang et al 2022), modulators (Han et al 2022;Edelstein et al 2022), logic devices (Yang et al 2017;El Haffar et al 2022;Sreevani et al 2022;Swarnakar et al 2023), demultiplexers (Mohammadi et al 2023;Butt et al 2023), Bragg reflectors (Zeng et al 2022;Pallavi et al 2023), sensors (Bensalah et al 2022;Bahri et al 2022;Lai et al 2018;Salah et al 2021;Salah et al 2022) and directional couplers (Nanda et al 2022;Zhang et al 2020). The optical demultiplexer is based on the bandpass filter with its optimized parameters such as type and length of resonators.…”

Ultra-wide bandstop infrared MIM filter using aperture coupled square cavities

“…Functional devices based on MIM plasmonic waveguide such as directional couplers [14,15], switches [16,17], splitters [18], sensors [19,20], optical gates [21,22] and antenna [23] have been designed. Tunable bandpass and bandstop MIM plasmonic filters can be employed in multiplexers and de-multiplexers [24][25][26], light speed controlling [27] and optical switching [28].…”