Active Plasmonic Components Research Articles

A top-down fabricated gold nanostrip on a silicon-on-insulator wafer: a promising building block towards ultra-compact optical devices.

A plasmonic waveguide is a fundamental building block for high speed, large data transmission capacity, low energy consumption optical communication and sensing. Controllable fabrication and simultaneous optimization of propagation loss and coupling efficiency with free space light are essential for the realization of ultra-compact passive and active plasmonic components. Here, we proposed gold nanostrips on a silicon-on-insulator wafer as plasmonic waveguides and first demonstrated the direct free-space light coupling and end-scattering detection of the top-down fabricated plasmonic waveguide. The scattering intensity from the terminal of a 6 μm long nanostrip can be improved experimentally over 34 times larger than that on the silica substrate. The controllable fabrication process renders the gold nanostrip on a silicon-on-insulator substrate a promising building block for ultracompact, monolithic integration and CMOS-compatible plasmonic devices in optical communication and sensing.

Active Plasmonics: Principles, Structures, and Applications.

Active plasmonics is a burgeoning and challenging subfield of plasmonics. It exploits the active control of surface plasmon resonance. In this review, a first-ever in-depth description of the theoretical relationship between surface plasmon resonance and its affecting factors, which forms the basis for active plasmon control, will be presented. Three categories of active plasmonic structures, consisting of plasmonic structures in tunable dielectric surroundings, plasmonic structures with tunable gap distances, and self-tunable plasmonic structures, will be proposed in terms of the modulation mechanism. The recent advances and current challenges for these three categories of active plasmonic structures will be discussed in detail. The flourishing development of active plasmonic structures opens access to new application fields. A significant part of this review will be devoted to the applications of active plasmonic structures in plasmonic sensing, tunable surface-enhanced Raman scattering, active plasmonic components, and electrochromic smart windows. This review will be concluded with a section on the future challenges and prospects for active plasmonics.

Magneto-optical response in bimetallic metamaterials

Abstract We demonstrate resonant Faraday polarization rotation in plasmonic arrays of bimetallic nano-ring resonators consisting of Au and Ni sections. This metamaterial design allows the optimization of the trade-off between the enhancement of magneto-optical effects and plasmonic dissipation. Nickel sections corresponding to as little as ~6% of the total surface of the metamaterial result in magneto-optically induced polarization rotation equal to that of a continuous nickel film. Such bimetallic metamaterials can be used in compact magnetic sensors, active plasmonic components, and integrated photonic circuits.

Plasmon–organic fiber interactions in diamond-like carbon coated nanostructured gold films

Gold is the most commonly used plasmonic material, however soft and prone to mechanical deformations. It has been shown that the durability of gold plasmonic substrates can be improved by applying a protective diamond-like carbon (DLC) coating. In this work, we investigate the influence of such protective layers on plasmonic interactions in organic–plasmonic hybrid systems. We consider systems, consisting of 1-Cyano-quaterphenylene nanofibers on top of gold nano-square plasmonic arrays, coated with protective layers of varying thickness. We numerically investigate the spectral position of surface plasmon polariton resonances and electric field intensity, as a function of protective layer thickness, using the finite-difference time-domain method. To confirm the numerically indicated field enhancement preservation on top of protective layers, we experimentally map the second harmonic response of organic nanofibers. Subsequently, we characterize the plasmonic coupling between organic nanofibers and underlying substrates, considered as one of the main loss channels for photoluminescence from nanofibers, by time-resolved photoluminescence spectroscopy. Our findings reveal that, for the investigated system, plasmonic interactions are preserved for DLC coatings up to 55 nm. This is relevant for the fabrication of new passive and active plasmonic components with increased durability and hence prolonged lifetime.

Benchmarking System-Level Performance of Passive and Active Plasmonic Components: Integrated Circuit Approach

Using criteria of bandwidth and energy consumption for signal guiding and processing, system-level figures of merit (FOMs) for both passive and active plasmonic circuit components are introduced, benchmarking their performance for the realization of high-bandwidth optical data communication on a chip. The FOM for passive plasmonic interconnects has been derived in terms of the system-level performance of the plasmonic circuitry, emphasising the bandwidth and power dissipation densities. These parameters are linked to the local waveguide characteristics, such as the mode propagation length, bend radius, and mode size. The FOM enables a comparison of the main types of plasmonic waveguides and can serve as a benchmark for future designs of photonic integrated circuits. A FOM for active photonic or plasmonic electro-optical, thermo-optical, and all-optical modulators is also derived to reflect the same benchmarking principles. A particular emphasis is made on establishing a practically oriented benchmark where the integral performance of the circuit, not the size or energy consumption of individual components, plays the defining role.

Active Nanophotonic Circuitry Based on Dielectric‐loaded Plasmonic Waveguides

Surface plasmon polaritons provide a unique opportunity to localize and guide optical signals on deeply subwavelength scales and can be used as a prospective information carrier in highly integrated photonic circuits. Dielectric‐loaded surface plasmon polariton waveguides present a particular interest for applications offering a unique platform for the realization of integrated active functionalities. This includes active control of plasmonic propagation using thermo‐optic, electro‐optic, and all‐optical switching as well as compensation of propagation losses. In this review, the principles and performance of such waveguides are discussed and the current status of the related active plasmonic components which can be integrated in silicon or other nanophotonic circuitries is summarized. A comparison of dielectric‐loaded and other plasmonic waveguides is presented and various material platforms and design pathways are discussed.

Gain enhancement in a V-shaped plasmonic slot waveguide for efficient loss compensation at the subwavelength scale

An active plasmonic slot waveguide comprising an inverted triangular metal wedge incorporated inside a V-shaped plasmonic groove with a low-index gain medium embedded between them is presented, and its guiding properties are investigated numerically at the wavelength of 1550nm. The presented waveguide is shown to be capable of supporting two fundamental plasmonic slot modes with high field localization to the V-shaped low-index slot region. Due to such strong optical confinement and significant field enhancement, the introduced gain in the slot could effectively compensate the propagation loss of the supported plasmonic modes. It is revealed that for the studied channel plasmonic slot and wedge plasmonic slot modes, notable gain enhancements are observable within a wide range of geometric parameters. For the considered structure with a 10–40nm-wide slot, the enhancements of gain can be as large as 11%–159% for the CPS mode while 43%–174% for the WPS mode. These values could be further improved by adopting even narrower slots. It is shown that, by introducing a gain medium with coefficients around hundreds of cm−1, the modal loss can be largely or even fully compensated, with a subwavelength mode area achievable simultaneously. These unique features of the studied V-shaped plasmonic slot waveguide might be useful for its potential applications in compact, active plasmonic components.

Modulation of surface plasmon wave by photo-induced refractive index changes of CdSe quantum dots

We demonstrate an all-optical modulation of surface plasmon resonance by photo-irradiation induced dielectric constant change of CdSe quantum dots on the gold surface. The dipole-dipole interaction between the surface plasmon and the photo-induced excitons in the dots gives rise to a shift in the surface plasmon resonance peak. This shift is found to sensitively reflect a tiny change in the dielectric constant, which is useful for investigating the nonlinear effect in active plasmonic components.

Modulation of the extraordinary optical transmission by surface acoustic waves

The numerical study of the acoustic (elastic) effect in periodically nanostructured metallic films exhibiting extraordinary optical transmission (EOT) deposited onto the top of a piezoelectric material is reported. Surface acoustic waves are generated in the piezoelectric substrate and their influence in the transmission spectrum of the EOT structure is studied. It is shown that low frequency acoustic waves can significantly tune the resonance frequency of the EOT structure and modulate the transmitted intensity. Acoustic waves appear as an interesting route to realize controllable EOT devices and other active plasmonic components.