Design of Wavelength-Adjustable Dual-Narrowband Absorber by Photonic Crystals With Two Defects Containing MoS2 Monolayer

Abstract

Wavelength-adjustable dual-band absorber has a potential impact on photonic circuits. While such devices are designed based on complicated structures, the use of a 2-D high-absorber MoS2 monolayer can alternatively simplify their design to a 1-D periodic structure. This article proposes photonic crystals with two defects as DMD to achieve dual narrowband defect modes, with M and D assumed to be the MoS2 and SiO2 layers, respectively. Thickness modulation, defect position, incident angle, and polarization of lights are investigated to find their impact on the absorption, wavelength, quality factor, full width half maximum (FWHM), depth of valley, and peak-to-peak distance of dual narrowband defect modes. This article shows that the wavelength of dual defect modes can be adjusted by the variation of distance of two defects with an absorption greater than 90%. The thickness of the D layer affects the depth of valley and wavelength of the defect modes while it has no influence on the peak-to-peak distance. Moreover, an increase in the incident angle leads to a systematic blueshift of the defect modes. The response of such structures can be systematically adjusted via various parameters to design dual narrowband wavelengths for application in photodetectors and photoluminescence and other optoelectronic devices.