Today's data centers' demands are growing at a blinding pace, requiring significant innovation to keep up. At the same time, the rate of scaling and innovation for traditional complementary metal-oxide-semiconductor (CMOS) technology is threatening to slow down with the end of Moore's Law imminent. 

One promising technology to enable the innovation needed for the modern data center is integrated photonics. 

An example of a photonic IC in a transceiver. Screenshot used courtesy of Intel

At the forefront of this effort is Intel, which recently announced the opening of a brand new integrated photonics research center. 

This article will take a glimpse at the benefits of photonics in the data center and learn more about Intel's new research center. 

Electrical Challenges in the Data Center 

Traditionally, data centers have relied on conventional electronics, which are concerned with the flow of electrons through copper conductors. These electronics have worked well historically; however, they have recently given researchers cause for concern, specifically for data-intensive applications. 

Today's data centers have increased significantly in physical size as well as in the amount of data they handle and the data rates they require. 

All of these things have generally led to longer interconnect cables, faster operating frequencies, and, subsequently, increased parasitic
impedances, explicitly pertaining to interconnects. 

Resistive and inductance parasitic impedance versus frequency. Image used courtesy of Hossam Sarhan and Mentor

These parasitics have come with harmful effects such as increased power consumption, thermal generation, and interconnect delay; all of these will only worsen as the demands on data centers increase. 

At the same time, Moore's Law is slowing down, meaning that on top of all of this, the general rate of electronic performance improvement has been significantly hindered. 

Why Integrated Photonics? 

Researchers have been hoping to try and counteract all of this by proposing the use of integrated photonics. 

Essentially, where conventional electronics are concerned with the flow of electrons through copper conductors, photonics is instead concerned with the flow of photons (i.e., light) through the use of dedicated waveguides. 

An example of an integrated photonic circuit. Image used courtesy of Edmund Optics

Photonics offers a variety of benefits over electronics in the data center. First off, photons, being light, travel much closer to the actual speed of light than electrons (10-100x faster) - meaning that integrated photonics can achieve faster data rates and higher bandwidths than conventional electronics. 

Beyond this, photons traveling through a waveguide experience almost no interference from other photons, increasing SNR and signal integrity in general. Finally, integrated photonics are much more energy-efficient than conventional electronics, resulting in power savings and increased thermal performance. 

Intel’s New Research Center 

To help push forward the state of integrated photonics, Intel announced that it was opening up a brand new integrated photonics research center. 

Formally dubbed the Intel Research Center for integrated Photonics for Data Center Interconnects, the new research center will develop new photonic technology for the data center with a primary focus on interconnect technology. 

Within this, the center will be researching topics, including: 

• Optical I/O technology scaling and integration
• CMOS circuits and link architectures 
• Package integration
• Fiber coupling

Intel has already announced several researchers who will be participating in the new research center, hailing from institutions including UC Santa Barbara, University of Washington, UC Berkeley, and more.  

Pushing Photonics Forward 

As data centers have scaled in size, speed, and volume, it has become clear that conventional electronics will not cut it any longer. Integrated photonics show promise to be a new generation technology that can help overcome some of the serious challenges facing data centers today. 

Intel's new research center has put itself at the forefront of this potential revolution, hopefully giving both the technology and the industry a serious boost. This new venture could also spur other companies, beyond ones like Synopsys' photonics design tools and Cadence's photonic integrated circuits (PICs), to get onto the photonics "bandwagon." Even Apple is rumored to be looking into this technology as well. 

All in all, it will be interesting to see where and how integrated photonics will develop and possibly become a mainstream technology.