The optical absorption of graphene layers prepared on top a one-dimensional photonic crystal (1DPC) is investigated theoretically. with 1DPC enhanced greatly over broad spectral range due to photon localization. can also be tuned by varying either the incident angle or distance between and 1DPC.

The optical absorption of monolayer MoS2 on top one-dimensional photonic crystal (1DPC) or metal films with spacer layers is theoretically investigated by extracting the permittivity from existing experimental results [K. F. Mak et al., Phys. Rev. Lett. 105, 136805 (2010)]. graphene 1DPC across a broad spectral range substantially enhanced because localization at micro-cavity films. can be tuned varying either distance between and back reflector thickness cover layers.

This paper describes the mechanism underpinning modal staging behaviour in screeching jets. An upstream-propagating subsonic guided-jet mode is shown to be active all stages of screech. Axial variation shock-cell spacing manifests spectral domain as a series suboptimal peaks. It demonstrated that may energized by interactions Kelvin–Helmholtz wavepacket with not only primary shock wavenumber peak, but also peaks; interaction suboptimals responsible for closing resonance loop multiple jet A...

We investigate the propagation of light waves in an aperiodic multilayer which is composed dielectric slabs arranged following Thue-Morse sequence. Both refractive index modulation and optical thickness are considered. The recursion relations transfer matrix elements derived to calculate transmission. By introducing a localization we explore properties system. Around particular center frequency (the midgap periodic quarter-wavelength multilayer), transmission more sensitive modulation.

We investigate THz absorption properties of graphene-based heterostructures by using characteristics matrix method based on conductivity. demonstrate that the proposed structure can lead to perfect because strong photon localization in defect layer heterostructure. The may be tuned continuously from 0 100% controlling chemical potential through a gate voltage. By adjusting incident angle or period number two PCs with respect graphene layer, one tailor maximum value. position peaks changing...

The propagation of coherent and partially light pulses through a one-dimensional photonic crystal ( 1DPC ) is investigated. dependence the evolution inside on incident angles effect coherence properties are discussed. pulse affected by pulse. As decreases, superluminal proprogation changes to subluminal propagation.

Photocatalytic nitrogen fixation has attracted much attention because of its ability to synthesize ammonia under mild conditions. However, the yield is still greatly limited by sluggish charge separation and extremely high N2 dissociation energy. Herein, two-dimensional Ti3C2 MXene ultrathin nanosheets were introduced construct Ti3C2/TiO2 composites via electrostatic adsorption for photocatalytic fixation. The activity experiments showed that after adding 0.1 wt% Ti3C2, composite reached...

The band structure and bandgaps of one-dimensional Fibonacci quasicrystals composed epsilon-negative materials mu-negative are studied. We show that an omnidirectional bandgap (OBG) exists in the structure. In contrast to Bragg gaps, such OBG is insensitive incident angle polarization light, width location cease change with increasing order, but vary thickness ratio both components, closes when equal golden ratio. Moreover, general formulations higher lower edges obtained by effective medium...

We theoretically investigate the phonon statistics of a quadratically coupled optomechanical system, in which an effective second-order nonlinear interaction between optical mode and mechanical is induced by strong driving field on two-phonon red-sideband resonance. show that antibunching can be observed even if strength much weaker than decay rates modes with weak fields respectively. Moreover, dynamically controlled tuning strengths phase difference fields. The scheme proposed here used to...

We report numerically large and complete photonic phononic band gaps that simultaneously exist in eight-fold phoxonic quasicrystals (PhXQCs). PhXQCs can possess simultaneous over a wide range of geometric parameters. Abundant localized modes be achieved defect-free for all polarizations. These exhibit multiform spatial distributions confine electromagnetic elastic waves area, thereby providing rich selectivity enlarging the interaction space optical waves. The simulated results based on...

A new transfer matrix method is developed based on the electromagnetic boundary conditions that Maxwell's equations required. Compared with traditional method, can be used to calculate optical absorption of any layer at position in stratified media. By using this we investigate properties a single graphene sheet one-dimensional photonic-crystal (1DPC) heterostructures. We demonstrate greatly enhanced up almost 100% by use 1DPC heterostructures because strong photon localization graphene.

The upstream-propagating waves of feedback loops in under-expanded impinging jets are investigated through several typical flow conditions. Schlieren image capturing and far-field acoustic measurement applied to the jet. structures related discrete tones extracted dynamic mode decomposition (DMD), standing formed by resonance identified from normalized amplitude fields chosen DMD modes. Spatial Fourier transforms along axial direction on modes obtain spatial wavenumber spectra, which two...

Extremely high-temperature and high-pressure requirement of Haber-Bosch process motivates the search for a sustainable ammonia synthesis approach under mild conditions. Photocatalytic technology is potential solution to convert N2 ammonia. However, poor light absorption low charge carrier separation efficiency in conventional semiconductors are bottlenecks application this technology. Herein, facile anatase TiO2 nanosheets with an abundance surface oxygen vacancies (TiO2-OV) via calcination...

We consider the lateral shift (LS) of a light beam reflecting from dielectric slab backed by metal. It is found that LS reflected can be negative while intensity almost equal to incident one under certain condition. The explanation for negativity given in terms interference waves two interfaces. also shown enhanced or suppressed some other conditions. numerical calculation on realistic Gaussian-shaped confirms our theoretical prediction.

The electronic properties of rubrene films exposed to oxygen have been studied by photoemission and x-ray absorption spectroscopies. Oxygen incorporation causes the highest occupied molecular orbital shift a ∼1.0 eV deep level due chemical bonds formed atoms with carbon within tetracene backbone molecules. Deformation induced C–O destroys delocalized nature orbitals. oxidized molecules in single crystal are proposed act as point defects that disturb long-range periodicity produce localized...

In this study, the near-field radiative heat transfer between graphene-covered metamaterials is investigated. The electric surface plasmons (SPs) supported by can be coupled with SPs graphene. significantly larger than that because of strong coupling in our studied frequency range. relationship flux and chemical potential for different vacuum gaps. Given graphene tuned external field, actively controlled modulating potential. certain gaps reach a maximum value when at particular value....

We report the properties of dual phononic-photonic band gaps and localized modes eightfold lithium niobate (LiNbO3) phoxonic quasicrystals (PhXQCs). Complete large are easily achieved despite low refractive index LiNbO3 substrate. Point defect intentionally introduced can form within both forbidden transparency bands over a wide range geometric parameters. Further analysis indicates that originate from intrinsic high-order rotational symmetry quasiperiodic structures, which resemble...

We study the transmission properties of photonic crystals consisting mu-negative material (MNM) and positive-index (PIM) using transfer matrix methods. The results show that there exists a band inside single-negative gap in proposed structure. central frequency is sensitive to thickness layers, while width only dependent on MNM which makes controllable. tunnelling mode localized strongly PIM electric field enhanced exponentially with increase layers. Transmittance can be increased by decreasing

The gate-tunable absorption of graphene layers with a resonant metal back reflector (RMBF) is theoretically investigated. We demonstrate that the RMBF can vary from nearly negligible to total by tuning external gate voltage within terahertz (THz) spectra range. Total THz less affected incident angle beams. This peculiar be attributed Fabry-Perot cavity effect, which enhances and reduces reflection graphene. graphene-RMBF structure also tailored in bandwidth center frequency changing...

In this study, terahertz (THz) absorption and transmission of monolayer MoS$_{2}$ was calculated under different carrier concentrations. Results showed that the THz is very small even high concentrations large incident angle. Equivalent loss total sum reflection one to three grades lower than graphene. The much larger traditional GaAs InAs two-dimensional electron gas. field-effect tubular structure formed by MoS$_{2}$-insulation-layer-graphene investigated. graphene reach saturation low...