News Article

Programming Light On A Chip


Research opens doors in photonic quantum information processing, optical signal processing and microwave photonics

Researchers from the Harvard John A. Paulson School of
Engineering and Applied Sciences (SEAS) have developed a new integrated
photonics platform that can store light and electrically control its frequency
(or color) in an integrated circuit.

The platform draws inspiration from atomic systems and could
have a wide range of applications including photonic quantum information
processing, optical signal processing, and microwave photonics.

“This is the first time that microwaves have been used to
shift the frequency of light in a programmable manner on a chip,” said Mian
Zhang, a former postdoctoral fellow in Applied Physics at SEAS, now CEO of
Harvard-spawned startup HyperLight Corporation and first author of the paper.
“Many quantum photonic and classical optics applications require shifting of
optical frequencies, which has been difficult. We show that not only can we
change the frequency in a controllable manner, but using this new ability we
can also store and retrieve light on demand, which has not been possible

The research was published in Nature Photonics.

Microwave signals are ubiquitous in wireless communications,
but researchers thought they interact too weakly with photons. That was before
SEAS researchers, led by Marko Loncar, the Tiantsai Lin Professor of Electrical
Engineering, developed a technique to fabricate high-performance optical
microstructures using lithium niobate, a material with powerful electro-optic

Loncar and his team previously demonstrated that they can
propagate light through lithium niobate nanowaveguides with very little loss
and control light intensity with on-chip lithium niobate modulators. In the
latest research, they combined and further developed these technologies to
build a molecule-like system and used this new platform to precisely control
the frequency and phase of light on a chip.

“The unique properties of lithium niobate, with its low
optical loss and strong electro-optic nonlinearity, give us dynamic control of
light in a programmable electro-optic system,” said Cheng Wang, co-first author
of the paper and now Assistant Professor at City University of Hong Kong. “This could lead to the development of
programmable filters for optical and microwave signal processing and will find
applications in radio astronomy, radar technology, and more.”

Next, the researchers aim to develop even lower-loss optical
waveguides and microwave circuits using the same architecture to enable even
higher efficiencies and, ultimately, achieve a quantum link between microwave
and optical photons.

“The energies of microwave and optical photons differ by
five orders of magnitude, but our system could possibly bridge this gap with
almost 100 percent efficiency, one photon at a time,” said Loncar, senior
author of the paper. “This would enable the realization of a quantum cloud - a
distributed network of quantum computers connected via secure optical
communication channels.”

The research was also co-authored by Yaowen Hu, Amirhassan
Shams-Ansari, Tianhao Ren from the Laboratory for Nanoscale Optics at Harvard;
and Shanhui Fan, Professor of Electrical Engineering at Stanford University. It
was supported in part by the National Science Foundation, the Office of Naval
Research, the Army Research Laboratory Center for Distributed Quantum
Information, and the Center for Integrated Quantum Materials (CIQM).

fabrication was performed at the Center for Nanoscale Systems at Harvard

Search the news archive

To close this popup you can press escape or click the close icon.
Register - Step 1

You may choose to subscribe to the PIC Magazine, the PIC Newsletter, or both. You may also request additional information if required, before submitting your application.

Please subscribe me to:


You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in: