Electrically tunable optical refractive index of a WS2 film on a SiC substrate

Ma, Yuke; Xu, Xiangang; Chen, Yanxue; Wang, Dong

doi:10.1117/1.oe.59.1.017107

Cited by 1 publication

(2 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The WS 2 film integrated PC is composed of a Si 3 N 4 (n = 2.02) slab encapsulated by two few-layer WS 2 films at the top and bottom, respectively, where the entire structure is etched with a square lattice of square holes (Figure 1a). The basic description of light-matter interactions in TMDC is extracted from the experimental references, [27][28][29] showing the results of refractive index in different bias voltages. The parameters of dielectric function in those works are obtained from Kramers-Kronig constrained analysis of the reflectance spectra, and the tunability of the refractive index of WS 2 is achieved mainly by strong excitonic effects and the high susceptibility of the excitons to the influence of free charge carriers.…”

Section: Moving Of Bics By Tuning Carrier Density In 2d Materialsmentioning

confidence: 99%

“…However, the surface coupling strength δ(|d|) is so weak that it can hardly affect the electric field of eigenmodes in the out-of-plane direction if the film of WS 2 is so thin, like in the monolayer case. [21] Therefore, few-layer WS 2 film is integrated into PC to enhance that effect on the resonant mode, [29,32] which can be more clearly evaluated by the variation of BIC in momentum space, denoted as Δk BIC (Figure 1b). Compared to the monolayer case, Δk BIC shows a larger shift in Γ-X direction in few-layer case, while it almost remains the same in bulk case, when changing the same amount of carrier density Δμ.…”

Section: Moving Of Bics By Tuning Carrier Density In 2d Materialsmentioning

confidence: 99%

See 1 more Smart Citation

Electrically Tunable and Robust Bound States in the Continuum Enabled by 2D Transition Metal Dichalcogenide

Zhao

Chen

Wei

et al. 2022

Advanced Optical Materials

View full text Add to dashboard Cite

However, limited by the finite periodic system, or fabrication errors, such as the roughness or the incline of the sidewall of holes in photonics devices, [7] radiative loss is hardly suppressed and only the quasi-BICs with finite radiative lifetime can be actually observed, exhibiting a Fano resonance in the scattering spectrum. [8] Such inevitable imperfections will hinder the development of high-Q on-chip photonic devices. [9,10] In recent years, merging BIC, as an efficient approach, is proposed to address this challenge, which originates from moving several BICs near the same spatial frequency in the momentum space. [11] The merging BICs can not only suppress the radiative losses of one eigenmode but also suppress surrounding resonances to achieve the high radiative Q-factor in a relatively broader range of spatial frequency, reducing the susceptibility of the structure, which makes them more robust to external perturbations. The numerical and experimental results of merging BIC at the Γ point on PC slabs were initially demonstrated in 2019, where the Q-factor was 12 times higher than the isolated BICs. [11,12] Following this design, an ultralow-threshold laser using merging BIC was proposed to explore its practical application in nanophotonics. [13] Besides, merging BIC at the off-Γ point was investigated in PC slab as well, which is constructed by a Friedrich-Wintgen BIC and an accidental BIC. [14] However, all the above approaches to generating merging BICs rely on controlling the geometric parameters of the structure including thickness or period, [11][12][13][14] which cannot dynamically tuned once the pattern is settled, thus limiting its reconfigurable performance of on-chip integrated photonic devices.

show abstract

Section: Moving Of Bics By Tuning Carrier Density In 2d Materialsmentioning

confidence: 99%

Section: Moving Of Bics By Tuning Carrier Density In 2d Materialsmentioning

confidence: 99%