Shifting Dynamics in Intercontinental Cabling and the Implications for High Reliability Fiber Coupler Manufacture and Supply

Ian Wilson, 8 June 2016

Gooch & Housego has been refining its approach to HI REL high reliability fiber coupler manufacturing by balancing its rapid response to market changes with meticulous attention to detail.

Global submarine telecom cable map
Global submarine telecom cable map. Image courtesy of RCR Wireless News
Ian Wilson - G&H HI REL Fiber Optic Component Product Manager
Ian Wilson, HI REL Product Manager

When a manufacturing facility producing high-reliability components for long-distance submarine cables suddenly has to triple its output of couplers for prestige clients, meeting this demand is literally a tall order. But this is exactly what happened at our Torquay facility.

Torquay has been making high-reliability (HI REL) fused couplers for the past 16 years, which we design and specify for never-fail deployment on the ocean floor. We have refined our manufacturing processes to ensure that these devices are completely reliable. Over this period, there has been a steady increase in the required bit-rate demanded by our customers, the major international communications companies, which is now up to 400 Gbit/s in some cases.

Delivery Milestone

This year we have shipped our 100,000th HI REL, high reliability fiber coupler to customers, which include all the major service providers in the Americas, Europe and the Far East. These devices are installed in undersea intercontinental links. If you use the internet, there is a greater than 50% chance that your data passes through G&H couplers.

Marine telecom cable laying ship
Marine telecom cable laying ship

So what has driven the recent surge in demand for these ultra-reliable undersea systems? The so-called “super-techs” – companies such as Apple, Facebook, Google, and Microsoft have created a significant market pull because they are directly involved in funding the networks they ultimately depend upon. We have also had to be responsive to this sudden growth in demand by rapidly recruiting a significant number of new staff and significantly expanding our manufacturing resources.

Considering the suite of products we develop and make, in every undersea repeater there is an erbium-doped fiber amplifier (EDFA), which includes 980 nm pump lasers and an erbium-doped fiber. This has the critical function on the seabed, every 100 km or so, of boosting the signal inside the cable to separate it from the noise floor. In each repeater there are up to eight amplifiers. Several hundred repeaters are installed on a typical transatlantic undersea link.

To put in perspective, Google’s Super-Fast Submarine Internet cable system,  utilizing six fiber pairs, each carrying one hundred wavelengths at 100 Gb/s (60 Terabits) is enough to carry 1600 DVD’s per second!

These HI REL components also feature: a 980 nm-1550 nm WDM system, which combines the 980 nm pump output with the 1550 nm signal to be ‘pumped’ up to strengthen and re-amplify the optical signal; there are also components to tap off signals; and the so-called “3dB components”, which split the signal by 50%.

The repeater pods provide a dry, constant-temperature environment for our couplers which are not hermetic. They are not overtly rugged; for example, the device is housed in a 3 mm diameter stainless 55 mm-long steel tube with two 250 µm buffered fibers coming out each end. It’s not built up with any ruggedization or sleeving. These small and incredibly simple but reliable components are responsible for carrying all of our internet traffic across from continent to continent around the world, without ever failing or complaining!

To ensure the best possible high reliability fiber coupler production, the manufacture of these pieces involves significant human input and observation. We believe that working “hands on” gives us the advantage in terms of quality, whether it is manual fiber stripping and handling; inserting the fibers into the manufacturing rigs; or observing processes and measurements.

Proof Testing

We use proof-testing at two stages in our manufacturing process. We clean the fiber and get it into a fit state for our fusion rigs, in order to prevent damaging the fiber’s surface. Then we strain test it to verify its strength before loading onto the fusion rig. It is also proof-tested at the end of the fusion process. We optically-test the devices before the temperature screening process and we then check to see there is no change in optical performance through screening. By this means, we are ensuring that the devices are strong and there are no mechanical flaws in the fused fiber.

Product Development

Recent product developments include the HI REL polarization beam combiners, something we commenced production of in 2016. This follows Gooch & Housego winning product quality approvals from several new clients. We are currently in negotiations with other global-scale client companies from Europe, North America and the Far East.

As a consequence of the recent surge in demand, we have had to introduce double-shifts in our plant to meet production demands. We have also had to employ some more staff on the production side. We are told that this latest increased production demand cycle could last for several years. Although there could be unforeseen market disruption, perhaps from China, we also anticipate that our market could grow further from the same territory. Furthermore, the recent approvals we have received from the Far East is a very good sign that we are considered to be a safe pair of hands as a supplier to this mission-critical and fast-growing sector.

Information relating to our HI REL products can be found on our fused fiber components page.