Novel 'Dual-Grating Assisted Directional Coupler' Developed For Nanophotonics

Jan 30, 2006

A collaborative research project between Innos (UK R&D company) and the universities of Surrey, Southampton and the Politecnico di Bari in Italy has developed a novel method for coupling light from an optical fibre to 200nm thick silicon waveguides in optical communications. The project has demonstrated the highest recorded coupling efficiency of 55%.

"There have been several published methods of achieving an effective coupling in theory, however no grating-based coupler has achieved as high a demonstrated efficiency as the work we have completed with Innos, Southampton University and Politecnico di Bari. It is also one of the best overall published results by any other method to date," says Research Fellow at the Advanced Technology Institute at the University of Surrey, Dr Goran Masanovic.

With the ever-decreasing size of communications devices optical technologies are at nanometre scale. The control and manipulation of light at this size (nanophotonics) can affect polarisation, loss and coupling issues. One of the key issues to be solved in nanophotonics is the coupling of light between an optical fibre and a semiconductor waveguide. Due to the difference in thicknesses and refractive indices between the two structures a direct coupling currently results in a loss as high as 20dB.

Coupling further becomes a problem as optic fibres typically have a core dimension of 9µm and the dimensions of silicon devices are often reduced to improve packing density and improve the performance of the photonic circuit. This often results in cross-sectional dimensions of silicon-based waveguides of ~1µm or less.

Commenting on the project, Sales and Marketing Director from Innos, Dr Alec Reader stated, "Advances such as fast silicon modulators and silicon lasers in silicon photonics has sparked interest recently not only from academia but from world-leading companies as devices are reduced in size. Coupling is just one roadblock to producing smaller devices, and we are pleased to have helped produce such an impressive proven result. We are expecting to work with the University of Surrey again on future European and EPSRC-funded projects."

Source: University of Surrey

Explore further: Researchers enhance nonlinear effects of optical metasurfaces

Related Stories

Dinosaur-times cockroach caught in amber, from Myanmar

8 hours ago

Geologica Carpathica has a paper on a new family of predatory cockroaches. Predatory? The authors, Peter Vrsansky and Günter Bechly, from the Slovak Republic and Germany, respectively, said that "unique adapta ...

Comcast must show what's next after collapse of deal

8 hours ago

Comcast, which reports financial results on Monday, faces some tough questions about what's next for the country's biggest cable company after its dreams of a far-reaching network collapsed with the death of its $45 billion ...

Japan eyeing 26% greenhouse gas cut: officials

8 hours ago

Japan is planning to pledge a 26 percent cut in its greenhouse gas emissions from 2013 levels, ahead of a global summit on climate change this year, officials said Friday.

Auditors: National Science Foundation suspends UConn grants

8 hours ago

The National Science Foundation has frozen more than $2 million in grants to the University of Connecticut after a foundation investigation found two professors used grant money to buy products from their own company, Connecticut ...

Recommended for you

The trillion-frame-per-second camera

Apr 29, 2015

When a crystal lattice is excited by a laser pulse, waves of jostling atoms can travel through the material at close to one sixth the speed of light, or approximately 28,000 miles/second. Scientists now have ...

New class of tiny chip-based thermometers

Apr 29, 2015

A new class of tiny chip-based thermometers being developed by PML's Sensor Science Division has the potential to revolutionize the way temperature is gauged.

User comments : 0

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.