“…By comparing the Hz field of mode III with the index-guided modes in W1 waveguide, we understand that mode III actually origins from the second index-guided 4 mode shown in Ref. [17] below the projected bulk modes. This mode has Ey component in the slot, and so the frequency is pulled up to be within the photonic band gap.…”
Abstract:We demonstrate experimentally an air-slot mode-gap photonic crystal cavity with quality factor of 15,000 and modal volume of 0.02 cubic wavelengths, based on the design of an air-slot in a width-modulated line-defect in a photonic crystal slab. The origin of the high Q air-slot cavity mode is the mode-gap effect from the slotted photonic crystal waveguide mode with negative dispersion. The high Q cavities with ultrasmall mode volume are important for applications such as cavity quantum electrodynamics, nonlinear optics and optical sensing.
“…By comparing the Hz field of mode III with the index-guided modes in W1 waveguide, we understand that mode III actually origins from the second index-guided 4 mode shown in Ref. [17] below the projected bulk modes. This mode has Ey component in the slot, and so the frequency is pulled up to be within the photonic band gap.…”
Abstract:We demonstrate experimentally an air-slot mode-gap photonic crystal cavity with quality factor of 15,000 and modal volume of 0.02 cubic wavelengths, based on the design of an air-slot in a width-modulated line-defect in a photonic crystal slab. The origin of the high Q air-slot cavity mode is the mode-gap effect from the slotted photonic crystal waveguide mode with negative dispersion. The high Q cavities with ultrasmall mode volume are important for applications such as cavity quantum electrodynamics, nonlinear optics and optical sensing.
“…A fit of the y and D spectra yields information for both the structure and single PhC Ellipsometric determination of negative permittivity P Dardano et al 2 layer at approximately 1.55 mm. The PhC structure was modeled by three layers: (i) the top 30 nm was modeled as a generic Lorentz oscillator, equation (2), for transverse magnetic polarization or as an Si-air mix (46.23% Si and 53.77% air) for transverse electric polarization; (ii) 1.47 mm of the Si-air mixture; and (iii) 160 nm of pure Si corresponding to the under-etch of the PhC. The PhC structure was then modeled to reside on the 870 nm silicon dioxide layer on the crystalline Si wafer.…”
Section: Resultsmentioning
confidence: 99%
“…Photonic crystals (PhCs) have reshaped the landscape of photonic devices 1 with such early applications as waveguides 2,3 and resonant cavities, 4 as well as multiplexing. 5 The power of PhCs and their unusual properties arises from the optical bandgap, which can be tailored by design.…”
In this work, we present the first experimental evidence of negative dielectric susceptibility in a two-dimensional silicon photonic crystal (PhC) with negative refractive index behavior. In the frequency range in which the effective refractive index n eff is equal to 21, the incident light couples efficiently to the guided modes in the top surface layer of the PhC metamaterial. These modes resemble surface plasmon polariton resonances. This finding was confirmed by ellipsometric measurements, demonstrating the isotropy of the PhC resonances. Such negative index PhC materials may be of use in biosensing applications. Light: Science & Applications (2012) 4 as well as multiplexing. 5 The power of PhCs and their unusual properties arises from the optical bandgap, which can be tailored by design. Recently, PhCs have been used more widely as a metamaterial with an effective negative refractive index.6-10 Light propagating in such a metamaterial can undergo a drastic change in group velocity, causing the light to bend away from the usual direction that is observed with a conventional refracting medium. Owing to the fine control over the optical bandgap of the PhC, the effective refractive index can exhibit optical antimatter behavior.7 For example, a set of circular holes etched vertically into a silicon slab in a hexagonal arrangement can produce an effective resonant refractive index of n eff 521 for light propagating along the length of the slab (perpendicular to the direction of the holes). Such a metamaterial strongly couples incoming light and can be used to transmit data with minimum losses over millimeter distances for lab-on-a-chip applications.
8The reflection spectra of patterned surfaces have been widely studied since the discovery of Wood anomalies in metallic gratings.
11In particular, Fano found a clear connection between the narrow anomalies and surface wave excitation that distinguished broad and sharp anomalies. 12 The theoretical understanding of this phenomenon has been provided by Hessel and Oliner. 13 Similarly, the resonances in PhC slabs have been analyzed in reflection and transmission.14 These resonances have been used to reconstruct the band structure 15 and equifrequency surface 16 of PhCs. Similar to surface plasmon polariton (SPP) resonances, the resonant anomalies allow for the propagation of otherwise forbidden modes. 15 Other analogies with SPP behavior arise for PhCs at frequencies where the refractive index turns negative. In this paper, we present an experimental study of the resonance effects directly connected with negative refractive index properties of PhC. Using standard ellipsometric measurements of the amplitude y and phase D of the ratio between the linear polarization reflection coefficients, we demonstrate that the change in the dielectric function of negative index PhC is similar to the change in the dielectric constant of a plasmonic structure.17 Similar to the Fano resonances, 17,18 the resonances in the y spectrum corresponding to a 180 6 phase change are slightly...
“…In 1990, Lehmann and Föll also discovered that very regular arrays of macropores with extremely large aspect ratio could be obtained in n-Si/HF system, and they explained the phenomenon using the "Space Charge Region" model [4]. The discovery of porous silicon opened new possibilities and extended applications in three-dimensional semiconductor structures [2], sensors [5,6], microelectromechanical system (MEMS) [7], photonic devices [8], and the like. In relation to such novel applications, the issue of porous silicon structures has also gained considerable attention in the last two decades.…”
Section: Introductionmentioning
confidence: 99%
“…Particular studies on the oxidization mechanisms at the silicon-electrolyte interface were also made in the past [4,9]. Some of the past studies have shown that the rate of oxidation is affected by electrolyte concentration, anodizing current density, and diffusion limitation of oxide forming (H 2 O) molecules [4,6]. Such studies have extended our understanding of the oxide forming mechanism for pore formations.…”
The rate of oxide formation during growth of pores structures on silicon was investigated by in situ I-V measurements. The measurements were designed to get two I-V curves in a short time (total time for the two measurements was 300 seconds) taking into account the gap (in mA/cm 2 ) for each corresponding voltage. The in situ I-V measurements were made at different pore depth/time, at the electrolyte-pore tip interface, while etching takes place based on p-type Si. The results showed increasing, decreasing, and constant I-V gap in time, for macropores, nanopores, and electropolishing regimes, respectively. This was related to the expected diffusion limitation of oxide forming (H 2 O) molecules reaching the electrolyte-pore tip and the anodizing current, while etching takes place. The method can be developed further and has the potential to be applied in other electrochemically etched porous semiconductor materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.