Directive emission of red conjugated polymer embedded within zero index metamaterials

Abstract: We numerically demonstrate an impedance-matched multilayer stacked fishnet metamaterial that has zero index with flat high transmittance from 600nm to 620nm. The effective refractive index

Plasmonic nanogaps for broadband and large spontaneous emission rate enhancement

We present the optical properties of a plasmonic nanogap formed between a silver metallic nanoparticle and an extended silver film that shows a strong enhancement in the spontaneous emission rate over the whole visible range. In particular, we use three-dimensional finite difference time domain calculations to study the spontaneous emission rate and the quantum efficiency of an emitting material placed within the gap region as a function of the geometrical parameters of the plasmonic nanogap. Our calculations reveal that the enhancements in the total decay rate can be divided into two regions as a function of wavelength; region I spans the wavelength range from 350 nm to 500 nm and peaks at approximately at 400 nm. Region II covers the spectral range between 500 nm and 1000 nm. The enhancements in total decay rate in region I are mainly dominated by Ohmic losses by the metal, while the enhancements in total decay rate in region II are mainly dominated by radiative decay rate enhancements. Furthermore, our calculations show over 100 times enhancement in the spontaneous emission rate in region II. We combine this with quantum efficiency enhancements of almost 30 times from materials with low intrinsic quantum efficiencies and only a small reduction in efficiency from those with high intrinsic quantum efficiencies. All results appear easily achievable using realistic geometrical parameters and simple synthesis techniques. These results are attributed to the strong field confinements in the nanogap region. The structures are of high interest for both the fundamental understanding of light mater interactions under extreme electromagnetic field confinements and also potential applications in quantum optics and Raman spectroscopy

Algebraic structures on parallel M2-branes

In the course of closing supersymmetry on parallel M2 branes up to a gauge transformation, following the suggestion in hep-th/0611108 of incorporating a gauge field which only has topological degrees of freedom, we are led to assume a certain algebraic structure for the low energy theory supposedly living on parallel M2 branes.Comment: 13 pages; v4: complete on-shell closure of supersymmetry, abstract changed, v5: gauge transformations are carefully define

Optical nanolithography using a scanning near-field probe with an integrated light source

An ultracompact near-field optical probe is described that is based on a single, integrated assembly consisting of a gallium nitride (GaN) light-emitting diode (LED), a microlens, and a cantilever assembly containing a hollow pyramidal probe with a subwavelength aperture at its apex. The LED emits ultraviolet light and may be used as a light source for near-field photolithographic exposure. Using this simple device compatible with many commercial atomic force microscope systems, it is possible to form nanostructures in photoresist with a resolution of 35 nm, corresponding to λ/10. © 2008 American Institute of Physics

Superembeddings, Non-Linear Supersymmetry and 5-branes

We examine general properties of superembeddings, i.e., embeddings of supermanifolds into supermanifolds. The connection between an embedding procedure and the method of non-linearly realised supersymmetry is clarified, and we demonstrate how the latter arises as a special case of the former. As an illustration, the super-5-brane in 7 dimensions, containing a self-dual 3-form world-volume field strength, is formulated in both languages, and provides an example of a model where the embedding condition does not suffice to put the theory on-shell.Comment: plain tex, 28 p

An optical nanocavity incorporating a fluorescent organic dye having a high quality factor

We have fabricated an L3 optical nanocavity operating at visible wavelengths that is coated with a thin-film of a fluorescent molecular-dye. The cavity was directly fabricated into a pre-etched, free-standing silicon-nitride (SIN) membrane and had a quality factor of Q = 2650. This relatively high Q-factor approaches the theoretical limit that can be expected from an L3 nanocavity using silicon nitride as a dielectric material and is achieved as a result of the solvent-free cavity-fabrication protocol that we have developed. We show that the fluorescence from a red-emitting fluorescent dye coated onto the cavity surface undergoes strong emission intensity enhancement at a series of discrete wavelengths corresponding to the cavity modes. Three dimensional finite difference time domain (FDTD) calculations are used to predict the mode structure of the cavities with excellent agreement demonstrated between theory and experiment

Goldstone Tensor Modes

In the context of brane solutions of supergravity, we discuss a general method to introduce collective modes of any spin by exploiting a particular way of breaking symmetries. The method is applied to the D3, M2 and M5 branes and we derive explicit expressions for how the zero-modes enter the target space fields, verify normalisability in the transverse directions and derive the corresponding field equations on the brane. In particular, the method provides a clear understanding of scalar, spinor, and rank r tensorial Goldstone modes, chiral as well as non-chiral, and how they arise from the gravity, Rarita-Schwinger, and rank r+1 Kalb-Ramond tensor gauge fields, respectively. Some additional observations concerning the chiral tensor modes on the M5 brane are discussed.Comment: 21 pp, plain tex. A sign corrected for agreement with convention

The Self-Dual String and Anomalies in the M5-brane

We study the anomalies of a charge $Q_2$ self-dual string solution in the Coulomb branch of $Q_5$ M5-branes. Cancellation of these anomalies allows us to determine the anomaly of the zero-modes on the self-dual string and their scaling with $Q_2$ and $Q_5$. The dimensional reduction of the five-brane anomalous couplings then lead to certain anomalous couplings for D-branes.Comment: 13 pages, Harvmac, refs adde

Retained self-inserted foreign body into the urethra associated with sequela urethral stenosis: a case report

INTRODUCTION: Self-insertion of foreign bodies into the urethra represents a heterogeneous group of cases concerning a wide variety of objects and involving multiple procedures and surgical techniques. CASE PRESENTATION: We report a case of self-insertion of an electric cable into the urethra by a 36-year-old Caucasian man for erotic reasons. The patient, who has an ambiguous history of self-inflicted penile strangulation in childhood and self-insertion of foreign bodies into the urethra in recent years but no psychiatric history, presented to the emergency department to remove the object introduced one week previously. He was - strangely - asymptomatic and presented neither dysuria nor urinary incontinence or hematuria. A physical examination revealed a penile scar corresponding to the strangulation and a palpable hard, thin mass in the perineal urethra. The biologic findings were normal. Plain film of the urinary tract showed a hollow tubular object, whose size and shape corresponded to those of the urethra. Rigid cystoscopy was performed, which revealed urethral stricture at the projection of the scar. Laborious urethrotomy was performed before reaching the 25cm long cable, which was found in the urethra and removed with difficulty due to stenosis. CONCLUSIONS: We encountered a particular case combining a self-introduced foreign body in the urethra and the sequelae of such manipulations, which is urethral stricture. We succeeded in treating both by endoscopy, which is not always possible in this situation