Acousto-optic modulation of photonic bound state in the continuum

Yu, Zejie; Sun, Xiankai

doi:10.1038/s41377-019-0231-1

Cited by 513 publications

(98 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Key elements for photonic integrated circuits such as waveguides, microcavities, directional couplers, (de)multiplexers, and modulators have recently been experimentally demonstrated in low-refractive-index waveguides on high-refractive-index substrates. [93,[98][99][100] A schematic of the envisioned photonic integrated circuits relying on BIC low-refractive-index waveguides on high-refractive-index substrates is depicted in Figure 4d. This platform used an easy-to-etch organic polymer on top of a lithium niobate layer where the light is guided.…”

Section: Bics For Light Guidingmentioning

confidence: 99%

Photonic Bound States in the Continuum: From Basics to Applications

Azzam

Kildishev

2020

Advanced Optical Materials

366

141

View full text Add to dashboard Cite

In theory, BICs are dark states with infinite radiative lifetime and generally require at least one dimension of the structure extending to infinity. [6] Similar conditions can also be obtained in localized systems of finite extent when the permittivity approaches zero. [5,11] However, in practice, due to the finite extent of structures, material absorption, and other external perturbations, BICs collapse to a Fano resonance with a limited radiative Q factor. Such resonances are known as quasi-BIC and they have been used to obtain very high Q resonances in numerous photonic systems to date. [6,8,12] Even though practical implementations of BICs are limited to quasi-BIC, in the literature, as well as in this review, quasi-BIC are commonly referred to as BICs. Another type of high-Q resonances called near-BIC is obtained in the vicinity of the BIC through detuning the system from the BIC regime. [9,13,14] Near-BICs can be explained by the Theory of Resonance Reactions by Fonda [13,14] as a bound state can exist in the continuum at an energy where some channels are open even when the open and closed channels are strongly coupled. If the Hamiltonian of the system differs slightly from the one that can produce such a bound state, a sharp resonance appears in all scattering and reaction cross-sections. Near-BIC resonances can be obtained over an interval of values of a specific parameter of the system, unlike BICs that are generally achieved at a single value of the parameter. [9,15] This is of importance for practical systems as it provides stability to fabrication errors and other imperfections. [12] It is also worth mentioning that the total Q factor (Q t) realizable through BICs is generally limited by the material loss. While the radiative Q-factor (Q r) at BICs can diverge, the non-radiative Q-factor (Q nr) is limited by material absorption and its inhomogeneous broadening, scattering from the structural disorder, and in-plane lateral leakage. It is therefore, important to have an accurate distinction between Q r and Q nr and account for non-radiative processes as generally the main contributors to the total Q." 1.2. BIC Types and Formation Mechanisms Since the time of initial prediction of BICs in photonics, they have been realized in numerous geometrical systems, including gratings, waveguides, metasurfaces, and photonic crystals. [4,7,9,16-24] Such a broad diversity of photonic systems supports different types of BICs that originate from various physical mechanisms. We will briefly highlight the different The introduction of bound states in the continuum (BICs) to photonics has revolutionized the way cavity design and light-matter interactions are thought about in general. BICs can have very high quality factors, even in open structures where access to radiation is permissible. Now, BICs found applications in a large class of areas, including nonlinear enhancement, coherent light generation, sensors, filters, integrated circuits, and many others. In this review, the different types of BICs in photonic systems,...

show abstract

Section: Bics For Light Guidingmentioning

confidence: 99%

Photonic Bound States in the Continuum: From Basics to Applications

Azzam

Kildishev

2020

Advanced Optical Materials

366

141

View full text Add to dashboard Cite

show abstract

Section: Acousto‐optic Effect and Its Applications For 2d Materialsmentioning

confidence: 99%

“…[184] The underlying mechanism is that through the photons and phonons coupling, it will give rise to a carrier density variation in the media, which further changes the complex refractive index of the transparent material, equivalent to the phase and absorption modulation. [29,71,185,186] Nowadays, the development of AO devices has hit a bottleneck where high-quality acousto-optic materials (e.g., the figure of merit and acoustic attenuation) are in great demand. [186,187] Although traditional AO materials have been widely investigated include TiO 2 , TeO 2 , and As 2 S 3 [188] suitable for visible to near-infrared wavelength; GaAs, ZnTe, GaP, ZnS, and CdS suitable for far-infrared wavelength, and among others, there still limitations in the applications such as the AO devices operating in the gigahertz range.…”

Section: Materials With Acousto-optic Effectmentioning

confidence: 99%

Tunable Optical Properties of 2D Materials and Their Applications

Ren

et al. 2020

Advanced Optical Materials

154

View full text Add to dashboard Cite

unlimited possibilities in the improvement of the performances of optoelectronic devices. [19-23] Beyond that, the properties of 2D materials can be tuned in situ by using different approaches [24-26] to expand the functionalities of optoelectronic devices. Out of them, the tunability in their optical properties has attracted great interest over the past decades where researchers dedicated to discovering various tuning methods to realize desired outcomes. [27,28] More excitingly, owing to the unprecedented electronic properties, high stretchability, magnetism, and thermal conductivity of 2D materials, different tuning approaches such as electrical gating, external strain stimuli, a static magnetic field, surface acoustic waves (SAWs), and thermal heating can be simultaneously adopted to participate the light-matter interaction, leading to the tailored and synergetic optical response of 2D materials. [29] Table 1 illustrates a brief advantages and weaknesses analysis between different optical tuning approaches of 2D and non-2D materials. There is a huge potential to revolutionize the optoelectronic devices by incorporating 2D materials with tunable optical properties. [30,31] So far, researchers have achieved flagship milestones in this area where a diverse set of high-performance optical devices are realized including modulators, photodetectors, optical sources, and optical switches. [32] In this review, we primarily focus on the theoretical and experimental researches of optical effects causing by various external stimuli in 2D materials. In Section 2, 2D materials with electro-optic effect and its application will be discussed, followed by piezophototronic effect and its application in Section 3. In Section 4, 2D materials with magneto-optic effect and its application will be discussed. Then, acousto-optic (AO) effect and its application, and thermo-optic (TO) effect and its application will be discussed in Sections 4 and 5, respectively. In the last section, the conclusion and perspective will be provided. 2. Electro-Optic Effect and Its Applications for 2D Materials 2.1. 2D Materials with Electro-Optic Effect In a broad sense, electro-optic effect is about an optical property change in the materials when applying an electric field. As shown in Figure 1, the refractive index of the material can be tuned in the presence of electric field due to the variation of charge carrier density. [29] This effect involves several Recent efforts have been heavily devoted to the development of next-generation optoelectronic devices based on 2D materials, due to their unique optical properties that are distinctly different from those of bulk counterparts. Given that the feature of flexible tunability is highly desired, various approaches have been demonstrated to efficiently modulate the optical properties, eventually enabling peculiar functionalities or realizing high-performance nanoscale devices. Here, this review focuses on recent advances in tuning the optical properties of 2D materials by external stimuli including elec...

show abstract

“…Because the BIC mechanism promises tight confinement of photons in a high-refractive-index material surrounded by a low-refractive-index environment, the reported optical BICs are mostly realized in the conventional structures, such as passive photonic crystal slabs [47], waveguide arrays [48], nanoparticles [49], and anisotropic dielectric layers [50]. However, it has also been reported that the optical BICs can exist in a high-refractive-index substrate with low-refractive-index waveguides atop by precisely tuning the dimensional parameters to achieve destructive interference between the leaky channels to the substrate [51][52][53], which can be explained by Friedrich-Wintgen BICs [54].…”

Section: Introductionmentioning

confidence: 99%

Nonlinear Bound States in the Continuum of Etchless Lithium Niobate Metasurfaces

et al. 2020

View full text Add to dashboard Cite

Optical bound states in the continuum (BICs) have recently been studied in a wide range of material systems, where light is perfectly confined in the continuous spectrum of radiating modes. In this paper, we reported periodic nonlinear metasurfaces on the etchless LiNbO3 platform, realizing the enhancement of second-order generation (SHG). All-dielectric heterogeneous metasurfaces are constructed by patterning a low-refractive-index polymer on a high refractive-index LiNbO3 film without etching. Due to BICs, light is localized in the LiNbO3 film where the excellent optical second-order nonlinearity is exploited. We demonstrated that with normal incident waves, symmetry-protected BICs are formed at near-infrared wavelength showing a vanishing linewidth in the transmission spectrum. In addition, to manifest the invisible BICs to detectable supercavity resonances at normal incidence, asymmetry is introduced into the system, degrading the symmetry-protected BICs to sharp resonances with a high Q factor. Furthermore, the second harmonic generation (SHG) of the etchless lithium niobate metasurface is studied, predicting that the SHG efficiency can exceed 10-3 with 30 MW/cm 2 of the pump intensity. The proposed strategy without facing the fabrication challenge of etching single-crystal LiNbO3 film opens a new avenue for the utilization of BIC in nonlinear optics of all-dielectric heterogeneous metasurfaces.

show abstract

Acousto-optic modulation of photonic bound state in the continuum

Cited by 513 publications

References 39 publications

Photonic Bound States in the Continuum: From Basics to Applications

Photonic Bound States in the Continuum: From Basics to Applications

Tunable Optical Properties of 2D Materials and Their Applications

Nonlinear Bound States in the Continuum of Etchless Lithium Niobate Metasurfaces

Contact Info

Product

Resources

About