Showing papers by "John B. Pendry published in 2015"

Transforming the optical landscape

Abstract: Electromagnetism provides us with some of the most powerful tools in science, encompassing lasers, optical microscopes, magnetic resonance imaging scanners, radar, and a host of other techniques. To understand and develop the technology requires more than a set of formal equations. Scientists and engineers have to form a vivid picture that fires their imaginations and enables intuition to play a full role in the process of invention. It is to this end that transformation optics has been developed, exploiting Faraday’s picture of electric and magnetic fields as lines of force, which can be manipulated by the electrical permittivity and magnetic permeability of surrounding materials. Transformation optics says what has to be done to place the lines of force where we want them to be.

Designing plasmonic gratings with transformation optics

Abstract: Matthias Kraft, Yu Luo, S. A. Maier, and J. B. Pendry Department of Physics, The Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom Centre for OptoElectronics and Biophotonics (OPTIMUS), School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue 639798, Singapore (Received 9 March 2015; revised manuscript received 2 July 2015; published 8 September 2015)

Coherent Four-Fold Super-Resolution Imaging with Composite Photonic–Plasmonic Structured Illumination

Abstract: We present a far-field super-resolution imaging scheme based on coherent scattering under a composite photonic–plasmonic structured illumination. The super-resolved image retrieval method, which involves the combination of 13 different diffraction-limited images of the specimen, is first developed within a Fourier optics framework. A feasible implementation of this optical microscopy technique working at 465 nm is proposed and its point spread function is investigated using full electromagnetics calculations. The 4-fold super-resolution power of the scheme, able to resolve 60 nm feature sizes at the operating wavelength, is demonstrated against both Abbe’s (imaging a single object) and Rayleigh’s (imaging two closely spaced objects) criteria.

Magnetic localized surface plasmons supported by metal structures

Abstract: Here we study the effect of realistic metal properties on the emergence of magnetic localized surface plasmons. These are subwavelength magnetic dipole modes supported by metallic particles that are corrugated with very long, curved grooves. By means of numerical simulations, we show that, despite the presence of losses in the metal, the concept of magnetic localized surface plasmons is general and can be applied to a broad range of frequencies, up to the mid-infrarred regime.

Automatically adjustable radiofrequency link

Abstract: An automatically adjustable radiofrequency link system includes a radiofrequency transmitter configured to transmit a signal at a frequency of transmission within an extremely high frequency (EHF) band. The system further includes a receiving device configured to receive the transmitted signal and provide feedback to a processing circuit communicatively coupled to the transmitter and the receiving device, wherein the feedback is related to the received signal. The processing circuit is configured to determine required signal properties based on the feedback and determine signal loss properties including an effect of atmospheric absorption, as a function of frequency; determine a modification to the transmitted signal using the signal loss properties and the required signal properties; and adjust the frequency of transmission to obtain a desired transmission signal using the modification.

Casimir effect memory cell

Abstract: A digital memory device includes a moveable element that is configured to move between a first stable position and a second stable position, where the moveable element comprises a first conducting area The digital memory device further includes a second conducting area on the surface of a substrate At the first stable position of the moveable element, a first gap exists between the first conducting area and the second conducting area At the second stable position of the moveable element, a second gap that is smaller than the first gap exists between the first conducting area and the second conducting area In at least the second stable position, an attractive Casimir force between the moveable element and the substrate holds the moveable element in the stable position

Method and system for pumping of an optical resonator

Abstract: A method of pumping an optical resonator includes directing light generated by a pumping light at the optical resonator, exciting a propagating surface state of the optical resonator at an interface of the optical resonator, and changing a propagating frequency of the light proximate the interface, where the changed frequency corresponds to a propagation frequency of the surface state. The optical resonator includes a photonic crystal and a material, where the interface is formed between the photonic crystal and the material.

Controlling light at the subwavelength scale

Abstract: This contribution describes a general strategy, based on transformation optics, to investigate a broad variety of plasmonic nanostructures. We exploit the fact that a finite nanoparticle with sharp geometrical features can behave like an infinite plasmonic system and can exhibit a continuous light absorption property over a broadband spectrum. Comprehensive discussions are provided on how the effects of nonlocality and edge rounding affect the local field enhancement as well as the energy and bandwidth of each plasmonic resonance. Generalization of this method to three dimensional situations will also be discussed. The largely analytic approach gives physical insights into the processes involved and suggests the way forward to study a wide variety of plasmonic nanostructures.