Scientists create diodes made of light

March 16, 2018, National Physical Laboratory
Scientists create diodes made of light
Credit: National Physical Laboratory

Photonics researchers at the National Physical Laboratory (NPL) have achieved the extra-ordinary by creating a diode consisting of light that can be used, for the first time, in miniaturised photonic circuits, as published in Optica.

Dr. Pascal Del'Haye and his team at NPL have created an optical version of a that transmits light in one direction only, and can be integrated in microphotonic circuits. This small-scale integration has been a major challenge in photonics because existing optical diodes require bulky magnets.

NPL's ground-breaking work has overcome the limitation of diodes based on bulky magnets, by using light stored in tiny chip-based glass rings to form a diode.

Diodes are well known in electronic . They transmit electric current in one direction but block the current in the backward direction. Diodes are essential components of nearly every electronic circuit and are used, for example, in battery chargers.

The novel technique was created by sending lots of light into a microresonator – a glass ring on a silicon chip, about the width of a human hair – and harnessing the circulating optical power to generate the diode effect.

Dr. Jonathan Silver, Higher Research Scientist at NPL, explains: "To create the optical diodes we used microrings that can store extremely large amounts of light. This meant that, even though we were only sending small amounts of light into these glass rings, the circulating power was comparable to the light generated by the flood lights in a whole football stadium—but confined into a device smaller than a . The light intensities enable the formation of a diode via a light-with-light interaction called the Kerr effect."

In their experiments, they have shown that the electromagnetic field of clockwise circulating light in these glass rings effectively blocks any counterclockwise circulating light.

Pascal Del'Haye, Principal Research Scientist of the project emphasises: "These diodes will, for the first time, open the door to cheap and efficient optical diodes on microphotonic chips, and will pave the way for novel types of integrated which could be used for optical computing.

"They could also have significant impact on future optical telecommunication systems, for more efficient use of telecom networks."

Leonardo Del Bino, Doctoral Student on the project, said: "A remarkable property of this novel diode is that the performance improves if the forward propagating light field is increased. This is very important, for example, when using the diode to protect chip-integrated laser diodes from back reflections."

Beyond the use for optical diodes, NPL's research on interaction of counterpropagating can enable new types of optical rotation sensors and optical memories.

Explore further: Researchers use sound waves to advance optical communication

More information: Leonardo Del Bino et al. Microresonator isolators and circulators based on the intrinsic nonreciprocity of the Kerr effect, Optica (2018). DOI: 10.1364/OPTICA.5.000279

Related Stories

New device could bring optical information processing

December 22, 2011

(PhysOrg.com) -- Researchers have created a new type of optical device small enough to fit millions on a computer chip that could lead to faster, more powerful information processing and supercomputers.

Researchers build a single-molecule diode

April 26, 2017

Researchers of the University of Barcelona have led a project to create a diode out of a 1 nm-sized single molecule with high rectification ratios. Diodes, commonly used in in everyday electronic devices, allow current to ...

Electronics and optics on one chip

November 9, 2017

Electronics and light don't go well together on a standard "CMOS' chip. Researcher Satadal Dutta of the University of Twente now succeeds in introducing a light connection into the heart of a semiconductor chip. In this way, ...

Recommended for you

How physics explains the evolution of social organization

June 20, 2018

A scientist at Duke University says the natural evolution of social organizations into larger and more complex communities that exhibit distinct hierarchies can be predicted from the same law of physics that gives rise to ...

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.