Output expansions, reliability enhancements prop up fiber-optic patch cord line

	Shenzhen Adtek's JP2P2116-1.5 model has at least 45dB PC, 55dB UPC and 60dB APC polishing return loss.

China suppliers of fiber-optic patch cords are looking to boost output and exports in preparation for rising orders.

The broadening adoption of 3G communications and FTTx broadband networking is fueling growth in China’s fiber-optic patch cords industry. The line is forecast to register 15 percent annual upturn in the next few years. Part of the surge in demand is generated by the local market, which is receiving a boost from the national policy to boost the broadband sector.

Shenzhen Adtek Technology Co. Ltd, which ships all its products to the EU and North America, expects a 40 percent sales increase this year. Zhejiang Sur-link Technology Co. Ltd is targeting at least 20 percent.

Mainland China makers are leveraging their cost advantage over foreign counterparts to secure the country’s position as the largest manufacturer of fiber-optic cables in the world. According to Shenzhen Adtek, products from the mainland are priced 10 percent less than those from Taiwan. To sustain this, many are optimizing their prefab rods and establishing solid partnerships with polysilicon providers to cut raw material expenses.

Most companies take advantage of the mainland’s abundant supply of fibers and purchase from local vendors. Some also source from Corning or other brands, depending on clients’ specifications. Almost all manufacturers have the in-house capability to make optical connectors, although several procure them from Japan or Taiwan for high-end versions. In general, imported inputs are 5 to 10 percent more expensive than local components. To ensure quality and consistency, many enterprises are strengthening IQC processes.

Besides keeping quotes competitive through cost-reduction programs, suppliers are improving reliability. R&D work is geared toward optimizing product specifications, particularly signal routing, insertion and return loss, durability, life cycle and operating temperature. To achieve this, many employ quality optical fibers and connectors.

Makers of the last, in particular, have been developing 2.5mm-diameter pins and sleeve coupling pipes to produce multiple FC, ST, SC, DIN 47255/47256, mini BNC, GFS-11/13 and 530 series. These boast lower insertion yet better return loss, and improved mechanical strength and operating temperature. At present, units made of precision ceramics dominate output.

Manufacturers are likewise enhancing the connector grinding process to elevate optic performance.

Further, some companies are strengthening customization capability to cater to buyers’ requirements better. Zhejiang Sur-link, for instance, is developing up to 20 distinct models. For Shenzhen Adtek, the focus will be on small yet highly integrated types suitable for LAN and back-panel use.

All export-oriented suppliers comply with ISO 9001:2000, and many have insertion loss and back reflection fully tested in accordance with Telcordia standards. Inspection of single-mode patch cords, in particular, covers the apex, radius and undercut on buyers’ requests.

Product selections conform to both well-known and emerging protocols, including the Ethernet, Fibre Channel, ATM and InfiniBand architectures.

Single-, multimode patch cords
Taiwan: Competition limits niche line to project-based orders
Hong Kong: Cables for audio applications dominate output

China suppliers’ selections can be categorized based on cable mode, structure and size, and connector type and polishing.

By cable mode, there are single, multiple and 10Gb configurations. The first type utilizes 9/125µm bulk cable, single-mode connectors on both ends and a yellow fiber jacket. Generally designed for high-speed, long-distance applications, the typical models under this category include SC-SC, SC-ST, SC-LC, SC-FC, ST-ST, ST-FC, LC-LC, LC-ST and LC-FC in both simplex and duplex kinds. The mainstream lengths are 1, 2, 3, 5 and 10m.

The second version supports 62.5/125 or 50/125µm bulk multimode fiber and multimode connectors on both ends. The fiber jacket is typically coded orange. It is suitable for low-speed, short-distance setups. The most-common units are SC-SC, SC-ST, SC-LC, ST-ST, LC-LC, LC-ST, MTRJ-MTRJ, MTRJ-SC, MTRJ-ST and MTRJ-LC in simplex and duplex. As for length, makers provide 1, 2, 3, 5 and 10m.

The 10Gb multimode patch cord kind is specially designed 50/125µm fibers optimized for the 850nm vertical-cavity surface-emitting laser-based 10Gb Ethernet. It is backward-compatible with existing network equipment and delivers close to three times the bandwidth of traditional 62.5/125µm variants. The jacket is usually aqua.

By structure, products from China can be divided into simplex and duplex patch cords, and ribbon fan-out cable assemblies. The first has one fiber and one connector on both ends of the cable, while the duplex type has two of each on either end. Each fiber is marked A or B, or different-colored connector boots are used to indicate polarity.

Ribbon fan-out cable assemblies, meanwhile, adopt ribbon fiber and connectors such as a 12-fiber MTP on one end. The other end has multiple fibers with ST, SC or LC.

As for connectors, some models employ the same type on both ends. Such may be ST, SC, LC or FC. Hybrid kinds have different connectors on each end. One may adopt SC and the other, LC, ST or FC.

Fiber-optic patch cords may also be distinguished based on the type of polishing used. Optical connectors, which are crucial in single-mode applications, are designed and polished to different shapes to minimize back reflection. For the last, the typical grades are -30, -40, -50 and -60dB.

There are three types of connector polishing under this group: PC or physical contact, UPC or ultraphysical contact and APC for angled physical contact.

The PC’s usual back reflection is less than -40dB and utilized for both single- and multimode applications. UPC and APC typically register lower than -50 and -60dB, respectively, and are for single-mode setups.

There are two other special varieties of fiber-opticpatch cords: mode-conditioning and polarization-maintaining. The former is applied in long-wave laser modules adopted in Gigabit Ethernet that need to operate with both single- and multimode fibers. It is usually duplex. The latter is made with a special fiber that maintains the polarization of light waves. It is adopted where high stability is required such as in instrumentation, measurement and setups that involve speeds above 10Gbps.

Multimode fiber-optic patch cords dominate both output and exports, piggybacking on their price advantage. Such products take up more than 60 percent of the total local production.

Multimode fiber allows different light propagation modes to transmit on a single fiber. As the core diameter is larger, they can adopt low-cost connectors and couplers, and are therefore less expensive than single-mode counterparts.

In general, the core diameter of a multimode fiber is between 50 and 100μm. The most-popular are 62.5/125, 50/125 and 100/140μm.

The core fiber number may be 2, 4, 6, 8, 12, 16, 20, 24, 36, 48, 60, 72, 84 or 96.

The cord jacket, depending on the application, can be manufactured as common, common anti-combustion, low-smoke halogen-free and low-smoke halogen-free anti-combustion. Typical multimode links have data rates of 10Mbps to 10Gbps over lengths of up to 600m.

Multimode fiber’s primary disadvantage is in long-distance, fast applications.

For such setups, single-mode configurations are preferred as they enable high-precision, broad-bandwidth usage. They allow only one propagation mode of light to pass through and have a thin core diameter of 8 to 10μm. The best-sellers are G.652, G.653 and G.655 with 8 to 10/125μm fiber.

Prices of patch cords declined by 10 percent in 2009. Despite stable input costs, makers expect the trend to persist the rest of this year due to fierce competition.

Many suppliers forecast a drop of 5 percent.

The rapid development of broadband Internet and FTTx network infrastructure, especially in Asia, has boosted Taiwan’s fiber-optic patch cord line. Fierce price competition from mainland China, however, is pushing companies in the island to pursue it only as a niche line and concentrate on project-based orders. The 30 to 50 local suppliers cater mainly to worldwide multiple system operators or MSOs that provide telecom, datacom and CATV services. Regional systems integrators that cooperate with MSOs are their second-largest clients.

Both single- and multimode models are available from Taiwan vendors. The latter type is used to enable communication over shorter distances such as within a building or on campus. These products have speed and distance limits but are less expensive than the first category.

Single-mode optical fibers are designed to carry only one ray of light mode and deliver higher bandwidth over a wide area. The equipment and construction outlay, however, cost more than multimode infrastructure. These are nevertheless mainstream.

Products with thinner diameters are increasingly becoming popular. Most releases measure 2.9x6, 2x4.2 and 1.8x3.7mm. The cable length, connector termination and color are mostly customizable.

Most fiber-optic patch cords from Hong Kong are for audio applications and incorporate 2, 3.5, 4, 5 or 6mm-diameter optical cable and Toslink plugs. Buyers can request models with Toslink-to-Toslink, Toslink-to-mini plug and mini plug-to-mini plug configurations. Suppliers can also attach the audio fiber-optic patch cords to digital or analog video cables such as S-Video and composite RCA in hybrid cable assemblies. The cords are mainly available in short lengths of 0.5 and 1m, and the less-common 2, 3, 5 and 10m.

Patch cords have color-coded jackets to indicate the fiber type. Some models use nylon protective sleeves featuring decorative patterns. Related accessories such as optical fiber splitters, adapters and fiber-optic decorative lights are also on offer. Varieties for datacom and telecom equipment typically have SC, LC, ST or MT-RJ plugs, and simplex/duplex and single/multimode versions. Glass, metal, plastic and ceramic ferrules are available.

Suppliers adopt bulk or retail packaging. Options for the latter include polybags with header cards, laminated gift boxes, and heat-sealed, sliding or snap-in blister packs. These are also offered in kits comprising other cables and accessories.

Hong Kong has at least 10 makers of fiber-optic patch cords. A number of mainland China and Taiwan manufacturers also have offices there.

Most local operations are veteran cable assemblers with factories in the southern part of the mainland. While they provide mostly models for audio applications, a few target datacom and telecom use. Besides patch cords, some suppliers release single- and multimode fiber-optic reels.

Cable assembly and wireless security system specialist Trisat Digital Ltd offers variants in Toslink-to-Toslink, Toslink-to-mini plug and mini plug-to-mini plug configurations. It also has hybrid fiber-optic audio+video cable assemblies and a metal series.

Jesmay Electronics Co. Ltd carries a selection of audio models with molded or assembly plug designs with protective sleeves. Aside from a choice of Toslink or mini plugs, units have assorted special features such as auto-retractable metal pins, spring tail, metallic shells and brightly colored jackets.