Canadian excellence in silicon photonics research was globally recognized this year when three researchers from Canada’s National Design Network® (CNDN) received “Top-Scored Paper” honours at OFC 2017, the leading international conference on optical communications.
Dr. Joyce Poon, Dr. Sorin Voinigescu (University of Toronto) and their teams, with Dr. Robert Mallard of CMC Microsystems, were honored in the Active Devices category for their development of a 3D integrated silicon photonic electro-optic transmitter. Also recognized in the category was Dr. David Plant (McGill University), for silicon photonic intensity modulators showing record-breaking modulation speeds. Dr. Lukas Chrostowski (University of British Columbia), was honored in the Passive Devices category for a new method of automatically tuning and stabilizing high-order optical filters in silicon photonics.
Sometimes called “the on-ramps to the future,” photonics innovations use light to enable advancements in power, speed and performance far beyond what’s possible with electronics.
Fibre optics, the backbone of global data communications, solved the problem of long-distance communications by converting electrical signals to optical ones. Now Dr. Poon’s group has figured out a way to adapt that capability to the immensely greater demands of short-distance communications, such as in data centres and high-performance computing, where transmitting vast volumes of data requires ever-greater amounts of power.
The technology demonstrated in the collaboration between University of Toronto and CMC solves some significant challenges in short-distance optical communications, offering high performance at low power, with the potential for cost-effective, high-volume manufacturability.
“Today, all these short links, whether from your computer to the wall outlet or in a data centre, are done with electrical cabling. And as data rates increase, so too does energy cost of transmitting the information,” says Poon, a Professor of Computer and Electrical Engineering who also holds a Canada Research Chair in Integrated Photonic Devices.
The challenge was to come up with the photonic integrated circuits and microsystems to efficiently transmit a lot of data using light, rather than electricity, over shorter distances.
“The demands for bringing the amazing performance of fibre optics to short distances are escalating,” she says. “That’s where silicon photonics comes in. It’s possible that by using the manufacturing infrastructure that the electronics industry has used for decades, we can mass-produce these photonic components at low costs.”
Their solution integrated a high-performance electronic integrated circuit with very high-end silicon photonics semiconductor technology using a CMOS driver. The workhorse of the microelectronics industry, CMOS offers the benefits of low cost and established manufacturing processes.
The University of Toronto team worked with CMC Microsystems throughout the development process. In addition to providing software design tools such as Cadence, COMSOL and ANSYS, CMC helped them with fabrication and integration of their microelectronic and silicon photonic chips. This collaboration carried out under the CMC Solutions program provided a fruitful learning experience for the graduate students involved. Indeed, the other co-authors of the OFC paper, Zheng Yong, Stefan Shopov, Jared Mikkelsen and Jason Mak, were all PhD students at the University of Toronto.
“Demonstrating the chip was exciting because we took a high-end CMOS chip and put it on top of the silicon photonics to achieve excellent performance. It was a nice surprise that the CMOS technology did even better than a more complicated, expensive, non-CMOS technology,” Poon says.
The performance of their microsystem was outstanding, achieving the highest dynamic extinction ratio for this type of transmitter at more than 40 Gigabits per second. It was also the first silicon photonic electro-optic transmitter to use a CMOS driver to operate beyond 32 Gigabits per second.
Looking to the future, the University of Toronto team aims to explore more advanced modulation formats that would put more information on the same bandwidth, increasing information-carrying capacity. Poon’s group is also developing more efficient, low-power modulators.
“While important in their own right, this year’s OFC honours also tell a great story about CNDN researchers and the resources that are made available to them,” Dr. Poon says.
“Our work is all related, and it paints an amazingly strong picture of how CMC’s investment in silicon photonics over the past several years, from training to technologies, is making an impact today,” she says. “And that impact is a direct result of us having access to technologies and expertise at a reasonable cost. It means we can take risks and try out new ideas,” says Poon.
“These honours reflect the outstanding work that is being done by Canada’s National Design Network in putting light to work,” says Dan Gale, Vice- President and CTO of CMC Microsystems. “No one else in the world has this experience in successfully prototyping innovations in photonics, and particularly silicon photonics. It is the technology of the future, and these awards show that Canada’s photonics innovators continue to lead the way.”