The pixel size imposes a fundamental limit on the amount of information that can be displayed or recorded on a sensor. Thus, there is strong motivation to reduce the pixel size down to the nanometre scale. Nanometre colour pixels cannot be fabricated by simply downscaling current pixels due to colour cross talk and diffraction caused by dyes or pigments used as colour filters. Colour filters based on plasmonic effects can overcome these difficulties. Although different plasmonic colour filters have been demonstrated at the micron scale, there have been no attempts so far to reduce the filter size to the submicron scale. Here, we present for the first time a submicron plasmonic colour filter design together with a new challenge - pixel boundary errors at the submicron scale. We present simple but powerful filling schemes to produce submicron colour filters, which are free from pixel boundary errors and colour cross- talk, are polarization independent and angle insensitive, and based on LCD compatible aluminium technology. These results lay the basis for the development of submicron pixels in displays, RGB-spatial light modulators, liquid crystal over silicon, Google glasses and pico-projectors.

A finite element method is applied to study the coupling between a nitrogen vacancy (NV) single photon emitter in nanodiamond and surface plasmons in a silver nanowire embedded in an alumina nanochannel template. We investigate the effective parameters in the coupled system and present detailed optimization for the maximum transmitted power at a selected optical frequency (650 nm). The studied parameters include nanowire length, nanowire diameter, distance between the dipole and the nanowire, orientation of the emitter and refractive index of the surrounding. It is found that the diameter of the nanowire has a strong influence on the propagation of the surface plasmon polaritons and emission power from the bottom and top endings of the nanowire.

Wavelength division multiplexing/demultiplexing in radio frequency communication networks and fibre-optic networks requires sophisticated hardware. One of the challenges in designing subwavelength optical networks is the simplification of the design. When considering the size reduction and feasibility, a design based on fewer constituent elements is highly desirable. Ultra-compact wavelength multiplexers/demultiplexers will play a vital role in all-optical communication networks of the future. The challenge is to use the simplest and fewest antenna elements to

For distances less 10 nm, a total energy transfer occurs from a quantum emitter to a nearby metallic surface, producing evanescent surface waves that are plasmonic in nature. When investigating a metallic nanohole supported on an optically dense substrate (such as diamond with nitrogen vacancy center), the scattering occurred preferentially from the diamond substrate towards the air for dipole distances less 10 nm from the aperture. In addition, an enhancement to the dipole's radiative decay rate was observed when resonance of the aperture matched the emitters wavelength. The relationship between an emitter and a nearby resonant aperture is shown to be that of the resonance energy transfer where the emitter acts as a donor and the hole as an acceptor. In conjunction with the preferential scattering behavior, this has led to the proposed device that operates in transmission mode, eliminating the need for epi-illumination techniques and optically denser than air superstrates in the collection cycle, hence making the design simpler and more suitable for miniaturization. A design criterion for the surface grating is also proposed to improve the performance, where the period of the grating differs significantly from the wavelength of the surface plasmon polaritons. Response of the proposed device is further studied with respect to changes in nitrogen vacancy's position and its dipolar orientation to identify the crystallographic planes of diamond over which the performance of the device is maximized.

We show theoretically and with numerical simulations that the direction of the in-plane scattering from a subwavelength optical antenna system can be controlled by the frequency of the incident light. This optical steering effect does not rely on propagation phase shifts or diffraction but arises from phase shifts in the localized surface plasmon modes of the antenna. An analytical model is developed to optimize the parameters for the configuration, showing good agreement with a rigorous numerical simulation. The simulation predicts a 25° angular shift in the direction of the light scattered from two gold nanorods for a wavelength change of 12 nm.