Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Photonics: The smaller the better

Waveguides that combine metallic and semiconductor structures can be made more compact
Increasing the areal density at which electronic components can be integrated onto a computer chip has always been key to the revolution of technological applications. However, achieving the same feat in the world of optics has been proven difficult as light waves cannot be compressed to sizes below their wavelength by conventional semiconductor-based optical waveguides.

Metallic structures, in theory, are able to provide such functionality through so-called plasmonic effects. In practice, however, the large optical losses have hampered the implementation of such schemes. Combining the benefits of conventional optics with plasmonics, Shiyang Zhu and co-workers at the A*STAR Institute of Microelectronics have now demonstrated how structures made of semiconductor and metals represent a more viable approach to effectively miniaturize optical circuits.

Plasmonic effects are based on motions of electrons at the surface of metals that act like an antenna on incoming light. They can be very effective to squeeze light into small volumes, although transport losses when guiding light along such small volumes are much higher than for conventional semiconductor waveguides (linear structures for guiding electromagnetic waves).

Zhu and colleagues observed waveguides based on semiconductor silicon. First, ridges are etched out of silicon chip to form the basis for the waveguide architecture. The surface of the silicon is then oxidized to provide electrical insulation of the silicon before it is covered in a thin copper layer (see image).

This architecture has the benefit of very efficiently squeezing light into the waveguide via the surrounding copper layer, but travels mostly along the core made of silicon and not the metal. Silicon is transparent for light at telecommunications frequencies and thus shows low losses. ”These waveguide structures are not only compatible with the fabrication processes of silicon computer chips,” says Zhu. “More importantly, the use of silicon and silicon oxide and related semiconductors enables further possibilities to potentially achieve other effects, such as light amplification, and control over the plasmon properties.”

Having previously shown that such waveguides are able to guide light efficiently, the researchers have now demonstrated a number of complex photonic structures, including the splitting of light beams at multiple junctions, the propagation of light across multiple kinks and steps, resonator structures that show light interference effects and many more.

“This is only a first step towards the varied and complex effects possible with these structures,” says Zhu. “The next step is to demonstrate some of the active functionality, especially to combine waveguides with ultracompact plasmonic light modulators based on related designs for complete functional nanoplasmonic circuits.”

The A*STAR-affiliated researchers contributing to this research are from the Institute of Microelectronics.


Zhu, S., Lo, G. Q. & Kwong, D. L. Components for silicon plasmonic nanocircuits based on horizontal Cu-SiO2-Si-SiO2-Cu nanoplasmonic waveguides. Optics Express 20, 5867–5881 (2012).

A*STAR Research | Research asia research news
Further information:

More articles from Power and Electrical Engineering:

nachricht 'Super yeast' has the power to improve economics of biofuels
18.10.2016 | University of Wisconsin-Madison

nachricht Engineers reveal fabrication process for revolutionary transparent sensors
14.10.2016 | University of Wisconsin-Madison

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>