نتایج جستجو برای: forbidden photonic band
تعداد نتایج: 163847 فیلتر نتایج به سال:
Electromagnetic band structure can produce either an enhancement or a suppression of spontaneous emission from two-dimensional (2-D) photonic crystal thin films. We believe that such effects might be important for light emitting diodes. Our experiments were based on thin-film InGaAs/InP 2-D photonic crystals at ambient temperature, but the concepts would apply equally to InGaN thin films, for e...
Linear waveguides in photonic-crystal slabs, two-dimensionally periodic dielectric structures of finite height, are fundamentally different from waveguides in two-dimensional photonic crystals. The most important distinctions arise from the fact that photonic-crystal slab waveguides must be index-confined in the vertical direction ~while a band gap confines them horizontally!. We present a syst...
Blue phase colloidal crystals and dielectric nanoparticle/polymer doped blue phases are demonstrated to combine multiple components with different symmetries in one photonic material, creating a photonic crystal with variable and micro-controllable photonic band structure. In this composite photonic material, one contribution to the band structure is determined by the 3D periodic birefringent o...
A new topology optimization algorithm is proposed based on bi-directional evolutionary structural optimization (BESO) method in order to design photonic crystals with maximum band gaps. The optimization process starts from a simple unit cell without band gap, and the photonic crystals are assumed to be periodically composed of two materials with different permittivity. Based on finite element a...
Coupled states of semiconductor quantum well (QW) excitons and photons in a two dimensional (2D) periodic lattice of microcavities are analyzed theoretically, revealing allowed bands and forbidden gaps in the energy spectrum of exciton polaritons. Photonic crystal exciton polaritons have spatially uniform excitonic constituent set by flat QWs, but exhibit periodic Bloch oscillations in the plan...
We present and use an algorithm based on convex conic optimization to design two-dimensional photonic crystals with large absolute band gaps. Among several illustrations we show that it is possible to design photonic crystals which exhibit multiple absolute band gaps for the combined transverse electric and magnetic modes. The optimized crystals show complicated patterns which are far different...
In this paper we consider the numerical computation of band gaps in photonic crystal fibres. We approximate the solution to a variational eigenvalue problem using the planewave expansion method (spectral Galerkin method). As well as presenting implementation and error analysis results we consider solving a modified problem where the piecewise constant coefficient function is replaced with a smo...
Among the optical structures investigated for optical sensing purpose, a significant amount of research has been conducted on photonic crystal based sensors. A particular advantage of photonic crystal based sensors is that they show superior sensitivity for ultra-small volume sensing. In this study we investigate polarization changes in response to the changes in the cover index of magneto-opti...
We recently reported on the realization of ultraviolet photonic crystal laser based on zinc oxide Appl. Phys. Lett. 85, 3657 2004 . Here we present the details of structural design and its optimization. We develop a computational supercell technique that allows a straightforward calculation of the photonic band structure of ZnO photonic crystal slab on sapphire substrate. We find that despite t...
Under certain conditions, a transparent photonic band can be designed into a one-dimensional metallodielectric nanofilm structure. Unlike conventional pass bands in photonic crystals, where the finite thickness of the structure affects the transmission of electromagnetic fields having frequency within the pass band, the properties of the transparent band are almost unaffected by the finite thic...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید