Embedded optics enabling higher bandwidth computing

Intelligence, surveillance, and reconnaissance () systems are driving the need for higher bandwidth computing and engineers have turned to ruggedized to meet that demand. In this Q&A with Gerald Persaud, Vice President, Business Development at , discusses the challenges in the design process and where designs are trending for embedded optical modules; ; and how , ISR, and systems are taking advantage of the technology.

MIL-EMBEDDED: Please provide a brief description of your responsibilities at Reflex Photonics and your group’s role within the company?

PERSAUD: My main responsibilities include increasing market penetration and revenues for optical modules; training customers and our sales force on the benefits of using embedded optical modules for military electronics; as well as defining and launching new optical modules based on customer needs.

My responsibilities also include providing high-bandwidth communication solutions to customers, establishing partnerships with other companies to offer a complete optical interconnect solution including optical , connectors, and cables. I also seek out new technologies to maintain our competitive edge.

MIL-EMBEDDED: What factors are driving the use of fiber optics in military applications?

PERSAUD: The high demand for national security is driving the needs for more advanced ISR systems. New ISR systems rely on high bandwidth computing that can only be practically met by fiber optics due to their low space, weight, and power (SWaP) needs. Many nations worldwide have witnessed considerable success by adapting newer ISR systems such as reconnaissance of satellites, unmanned aerial systems (UAS) as well as manned platforms. (Source Markets and Markets)

MIL-EMBEDDED: Who is investing the most in fiber optic technology and who are the leading suppliers of rugged embedded optical modules?

PERSAUD: Military companies that manufacture radar systems such as active electronic scanned arrays (AESA) are investing heavily in embedded optics due the numerous advantages of fiber optics over copper for high bandwidth .

MIL-EMBEDDED: What military applications were the first to adopt the technology?

PERSAUD: Fiber optics been used in the military for secure communications for a long time mainly because they produce no electromagnetic signature that can be detected.

Unlike electrical cables, fiber optic cables emit no and therefore cannot be scanned with an antenna. Therefore, communications over fiber optics is far more secure than electrical transmission. 

Today, secure communication is a serious threat to national security as many nations have the ability to hack into secure networks and steal sensitive information. High security networks needs be isolated by firewalls. However, the ubiquitous nature of the Internet makes it difficult to perfectly isolate networks. One can imagine a situation where an enemy can hack into a network and take control of critical infrastructure and cause massive chaos. Securing networks and information is probably the most critical function of any effective defense in today’s ultra-connected world.

MIL-EMBEDDED: What are the challenges in the design process with the use of fiber optics in military applications?

PERSAUD: Our main challenge is selecting the right optical modules to meet the operational environment. There are many types of optical modules offered at very low cost for commercial operations such as data centers. However, these modules are designed for cost and not for operation in harsh environments. Most military applications require products to operate in extreme temperatures of -55 to 100 degrees Celsius. Reflex Photonics optical modules are constructed from high temperature low thermal expansion materials to [meet these requirements]. For example, our optical modules can be subjected to temperatures up to 260 degrees Celsius with no impact to its reliability.

MIL-EMBEDDED: What VITA standards include the specification of Optical Interconnect? And is there an increased demand for open standards for your defense customers?

PERSAUD: Reflex Photonics sees a clear need from its customers for open standards on an optical interconnect and is an active participant in the VITA standards committee.

The main VITA standards for VPX Optical Interconnect are .1 and 66.4. These standards define optical connectors for blind mating to backplanes. They allow one to quickly replace a circuit card without undoing any optical cables. The main drawback to using these connectors is they occupy a lot of space on the circuit card. They require optical transceivers and onboard cables to drive them. The combination of optical transceiver, optical cable, cable routing mechanics, and optical connector can easily use 30 percent of a 3U board real estate. Today’s military systems cannot afford to use so much space for optical communications. To solve this problem Reflex Photonics recently released LightCONEX, a new optical backplane connector that integrates the optical transceiver directly into the connector.

Figure 1: Reflex Photonics LightCONEX is blind mate optical interconnect for VPX embedded computing systems, consists of a module connector and a backplane connector compatible with the VITA 66.4 standard. Photo courtesy of Reflex Photonics.
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MIL-EMBEDDED: What are the power benefits or cons of using optical interconnects in a system?

PERSAUD: Optical transceivers have a clear advantage over copper interconnects at bandwidths beyond 10 Gbps/channel. While electrical interconnects can be made to operate at speeds up to 56 Gbps they require a lot of to work. This level of signal processing can use more than twice as much power as using an embedded optical transceiver. The main reason embedded optical transceiver are more power efficient is they can be placed close to the electrical transceiver so there is no significant signal losses in the short electrical connections. As well, embedded optical modules have a low profile so their cooling efficiency is high due to the increased surface area for cooling.

MIL-EMBEDDED: Where do you see fiber adoption 5-10 years down the road and what trends do you expect for embedded optical modules in aerospace and defense?

PERSAUD: The benefits in SWaP and bandwidth for military systems will force next generation systems to use fiber-optics; copper is simply not a competitive system interconnect technology for today’s advance computing systems. The challenge for many companies now is to how to transition to fiber optics to maintain their competitive edge. Companies must learn how to select the best optical interconnect technologies for their applications.

The main trends are: more I/O with less space; higher channel bandwidths such as 10G, 25G, or 56G; less space, weight, and power needed for the optical interconnects; and more rugged embedded optical modules that can operate in very harsh environments such as space.

Gerald Persaud is responsible for overseeing global marketing, business development and customer initiatives related to the Reflex Photonic’s product lines, as well as managing product development and customer technical support. He has more than 20 years experience in telecom and defense. Prior to joining Reflex Photonics Gerald held senior management roles in engineering and business development at Nortel, General Dynamic Canada, and Celestica. Gerald has developed many leading products in optical communication, , and advanced computing. He also won the largest design contract ever in Celestica for an OTN switch. Gerald holds a B.S. in Electrical Engineering at McMaster University.