Cutting Edge Photonic Solutions Transform Data Center Operations

By Emily Newton

Silicon photonics uses silicon as an optical medium. People involved in such applications are interested in making photonic integrated circuits (PIC) that could improve optical communication, high-speed data transfers, and more. How could these cutting-edge photonic solutions support the current and future needs of modern data centers?

Enabling Faster And More Energy-Efficient Applications

One of the emerging concerns about artificial intelligence’s rampant popularity is that data centers may eventually encounter bottlenecks caused by node-related information transfer limitations. Current systems use fiber-optic cables to transfer data, but the associated nodes may be up to 1 kilometer apart. Additionally, converting electrical data to an optical format and back during the process is energy-intensive and inefficient.

However, engineers developed an alternative that relies on photonic chips. It uses one laser to generate hundreds of distinct wavelengths. Since each can simultaneously transfer independent data streams, this approach is more straightforward and more energy-efficient than current alternatives.

Additionally, this example shows the powerful results of silicon photonics. Both the silicon chip that transmitted the data and the component that received the optical signal and converted it to an electrical one were on the millimeter scale, smaller than a human fingernail.

The researchers based their proof-of-principle demonstration on 32 wavelength channels, but they said they could scale their innovation to accommodate more than 100. Moreover, experiments showed this setup could transmit 16 gigabits per second on each test channel. Accuracy also was extremely high, with less than 1 bit of error from 1 trillion transmitted.

Besides impressive scalability and speed, this work could open new silicon photonics data center possibilities due to its ease of fabrication. Silicon chip manufacturing can occur in the same facilities that currently create the microelectronic chips found in smartphones and other popular consumer products.

This project is in the early stages, but the next step to potential commercialization is to combine the photonics with control and drive electronics that work on the chip scale.

Supporting Data Center Efficiency

Efficiency and reliability are top-of-mind concerns for those working at data centers. Outages can be extraordinarily costly. A 2022 survey that found 45% of respondents said the incidents cost them between $100,000 and $1 million.

The people working at those facilities must follow many best practices to maintain efficiency and avoid outages, including choosing optimal cooling solutions and purchasing high-quality racks. However, the data center’s infrastructure is also critical. For example, optical interconnects act as bridges between two or more facilities, supporting the rapid transfer of information.

When a market research firm analyzed projected activity for silicon photonics from 2023 to 2028, the researchers cited data centers as a significant driving factor shaping that period. The analysts said the implementation of silicon photonics in data center technologies will become a major factor stimulating expansion. Additionally, the overall market will show a 28.5% compound annual growth rate, resulting in $5 billion of total worth by 2028.

Facilitating New Silicon Photonics Data Center Applications

Researchers have developed new polymer materials, which they say will make fabricating interconnects between silicon chips and optical printed circuit boards easier. Such progress could accelerate efforts to improve silicon photonics data center applications.

They have an adjustable refractive index that is controllable with ultraviolet light and has low optical losses. Additionally, the polymers enable printing a single-model optical interconnect directly into a dry film. Even better, this can occur with a low-cost, high-throughput lithography system that many manufacturers are already familiar with because they use it to make chip-based photonic components.

The group said their work could make data centers and the internet infrastructure work more efficiently. They specified that optical interconnects can increase data throughput but generate less heat than their electronic counterparts.

To demonstrate how they worked, the team deposited them onto ion-exchange glass waveguide arrays. Then, they printed the materials that would allow light to move out of one array and into a second one adjacent to the first. Tests showed this strategy worked well without significant coupling losses as light traveled within or between the interconnects and other parts.

However, the researchers hope to enhance how the material performs at high temperatures and improve its refractive index contrast. Making such progress would increase tolerance to manufacturing variations and allow using solder reflow processes on the interconnect.

This work could also benefit related applications. One example is cloud computing, which depends heavily on data centers. Statistics show more than 90% of organizations already use cloud infrastructure, emphasizing its high adoption rate.

Silicon Photonics Improves Data Center Performance

Since data centers have become so integral to society, people working in the industry continually look for practical ways to optimize them. These examples show how silicon photonics will undoubtedly play an important role in the innovations to come. Although the developments are not yet commercially available, what groups learn about them in these early stages will inform their progress on those and other projects.