If there is one thing across domains, that is growing exponentially, it is the amount of data generated and acquired. No matter what industry or discipline is, data about processes, data about customers, and data on cross-functional procedures is constantly being generated, acquired and/or secured. Transmitting this data for any purpose becomes more and more difficult and data traffic has become a real issue for most ventures.
At this rate, the transmission and data capacity of state-of-the-art telecommunications infrastructure must double roughly every two years to sustain high levels of performance. That means that even now, technology companies such as Intel and Cisco have to set their sights on the hardware of 2024 and beyond to stay competitive. But, the researchers of the UC Santa Barbara’s electrical and computer science engineering department, have dared to reach roughly a decade into the future with the recent development of their mode-locked quantum dot lasers on silicon.
The Bower’s group hardware is a high-channel-count, 20 gigahertz, passively mode-locked quantum dot laser, directly grown, for the first time, on a silicon substrate. With a proven 4.1 terabit-per-second transmission capacity, it leaps an estimated full decade ahead from today’s best commercial standard for data transmission, which is currently reaching for 400 gigabits per second on Ethernet.
The technology is the latest high-performance candidate in an established technique called wavelength-division-multiplexing (WDM), which transmits numerous parallel signals over a single optical fiber using different wavelengths (colors). It has made possible the streaming and rapid data transfer we have come to rely on for our communications, entertainment and commerce.
The Bowers Group’s new technology takes advantage of several advances in telecommunications, photonics and materials with its quantum dot laser – a tiny, micron-sized light source – that can emit a broad range of light wavelengths over which data can be transmitted.
According to Songtao Liu, the lead author of the paper, their focus was on getting a more coherent wavelength generated in one cheap light source. Quantum dots can offer you a wide gain spectrum, and that’s why they could achieve a lot of channels – 64 to be precise, spaced at 20 GHz, and can be utilized as a transmitter to boost the system capacity.
The laser is passively ‘mode-locked’ – a technique that generates coherent optical ‘combs’ with fixed-channel spacing – to prevent noise from wavelength competition in the laser cavity and stabilize data transmission.
This technology represents a significant advance in the field of silicon electronic and photonic integrated circuits, in which the primary goal is to create components that use light (photons) and waveguides, unparalleled for data capacity and transmission speed as well as energy efficiency, alongside and even instead of electrons and wires. Silicon is a good material for the quality of light it can guide and preserve, and for the ease and low cost of its large-scale manufacture.
This quantum dot laser, and components like it, are expected to become the norm in telecommunications and data processing, as technology companies seek ways to improve their data capacity and transmission speeds. Data centers are now buying large amounts of silicon photonic transceivers.
The opportunities in this discipline are only growing. From research and development to setting industry trends, the field of electrical engineering and computer science engineering are leading the game. It is undeniable that this is a minefield of great opportunities for students looking to pursue a career in this. But, it is crucial that the foundation is laid out at a credible institution such as the International Center for Applied Sciences, Manipal. Their hands-on training and opportunities for study abroad are nothing but beneficial for students. They understand and identify great avenues for their students and lead them there through vigorous training and research, which are the building blocks of further opportunities both abroad and in India.