Waveguiding and detecting structure for surface plasmon polaritons on silicon

June 25, 2014
Schematic diagrams and electric field intensity distributions for (a) a multi-slit structure, (b) a disk array, and (c) no diffraction structure at the waveguide end.

Toyohashi Tech researchers have developed a simple, low-loss waveguide for Surface Plasmon Polaritons (SPPs) that is applicable to nanoscale photonic integrated circuits on silicon.

Surface plasmon polaritons (SPPs) are waves that propagate along the surface of a conductor and collective oscillation of electrons coupled with the optical field at the nano-scale beyond the of propagating light waves. Recently, there is increasing interest in SPPs as signal carriers in nanoscale to increase the degree of accumulation and reduce power consumption.

However, low-loss SPP waveguides with detectors have not been developed for applying to nanoscale integrated circuits.

Now, Mitsuo Fukuda and his group at Toyohashi Tech have developed a simple, low-loss waveguide for SPPs that is applicable to nanoscale integrated circuits.

A thin metal film deposited on a was terminated with a diffraction structure (a multi-slit or a metal disk array) at the end to guide the SPPs transmitted on the surface (air-metal interface) to the opposite side of the metal (metal-silicon interface). A Schottky barrier is formed at the metal-silicon interface, and the free electrons in the metal are excited by the guided SPPs and then cross over the barrier. The overflowing electrons result in observable photocurrents.

The waveguide developed in this research enabled the efficient propagation of SSPs in 1550-nm-wavelength bands (transparent to silicon) along the Au film , and the photocurrents were much larger than for waveguides without the diffraction structure (26 times for the grating structure and 10 times for the disk array).

This waveguide device is expected to contribute to nanoscale photonic integrated circuits on silicon.

Explore further: Nanoscale waveguide for future photonics

More information: M. Fukuhara, M. Ota, H. Sakai, T. Aihara, Y. Ishii, and M. Fukuda. "Low-loss waveguiding and detecting structure for surface plasmon polaritons." Applied Physics Letters, 104, 081111 (2014). DOI: 10.1063/1.4866792

Related Stories

Nanoscale waveguide for future photonics

May 31, 2011

The creation of a new quasiparticle called the "hybrid plasmon polariton" may throw open the doors to integrated photonic circuits and optical computing for the 21st century. Researchers with the U.S. Department of Energy ...

Recommended for you

Partitioning by collision

February 5, 2016

An ensemble consisting of a binary mixture of particles of equal size can partition itself into its component fractions - provided that the two species differ in their diffusion constants.

Leiden physicists entangle four rotating photons

February 3, 2016

For the first time, scientists have entangled four photons in their orbital angular momentum. Leiden physicists sent a laser through a crystal, thereby creating four photons with coupled 'rotation'. So far this has only been ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.