Have You Used Mode Conditioning Patch Cables in Data Center?

Transceiver modules used in Gigabit Ethernet (1000BASE-LX) can only operate over single-mode fiber, which will pose a problem if an existing fiber network utilized multimode fibers. Therefore, to solve this problme, we must provide a migration path that can continues to reuse the installed multimode cable plant. However, launching a single-mode laser into the center of a multimode fiber can generate multiple signals which will confuse the receiver at the end of the fiber. These multiple signals, caused by different mode delay (DMD) effects, severely limit the cable distance lengths for operating Gigabit Ethernet. To solve this problem, mode conditioning patch cable is designed. This text will give some detailed information about mode conditioning patch cable.

Mode conditioning patch cable (MCP), also referred to as conditioned launch fiber cable, is a duplex multimode fiber jumpers that has a small length of single-mode fiber at the start of the transmitting length. There are two multimode fibers at one end, while one single-mode and one multimode fiber at the other end. When you launch your laser into the small section of single-mode fiber, the other end of the single-mode fiber will be coupled to multimode section of the cable with the core offset from the center of the multimode fiber. Thus, the laser light misses the “dip” and this new launch condition is similar to typical multimode LED launches. Mode conditioning patch cable is utilized specifically in Gigabit Ethernet 1000Base-LX/LH applications where the objective is deploying new high-speed 1000Base-LX routers, switches, or optical transceivers within existing multimode system backbones. The following picture shows the construction of a mode conditioning patch cable.

The mode conditioning patch cable is installed between transceiver and patch panel. Two mode conditioning patch cables are required per installation. To install the patch cable, follow these steps:

• Plug the single-mode fiber connector (yellow leg) in to the transmit bore of the transceiver.
• Plug the other half of the duplex connector into the receive bore of the transceiver.
• At the other end of the patch cable, plug both multimode connectors into the patch panel.
• If you connect the patch cable directly to the network cabling, or patch panel, you may need to install a female-to-female adapter to allow the cables to be connected together.

Notes: Make sure that the patch cable should has appropriate connectors on each end, and has multimode fibers that match the characteristic of the multimode fiber in your network. The most important is that the core diameter of the multimode patch cable must match the core diameter of the multimode infrastructure (either 50 microns or 62.5 microns).

After reading the basic concept and installation procedure of mode conditioning patch cable, do you know when they should be used? The following tips can give you some suggestions.

• Mode conditioning patch cables are often used in pairs, which means that you will require a mode conditioning patch cable at each end to plug the apparatus to the cable plant. So you need to order mode conditioning cables in even numbers.
• When using mode conditioning patch cable, it is essential to connect the yellow leg which is the color of single-mode to connect the transmit side of the equipment (single-mode Gigabit transceiver) while connecting the orange leg (multimode connector) to the receive side.
• The requirement for MCP cable is specified only for 1000Base-LX/LH transceivers transmitting in the 1300nm window and in applications over multimode fiber, but should never be used in 1000Base-SX links in the 850nm window.
• Besides, mode conditioning patch cable can only convert single-mode to multimode. If you want to convert multimode to single-mode, then a media converter will be required.

Mode conditioning patch cable is a really significant solution to the problems we met in data transmission. From the above introduction, we get basic information about mode conditioning patch cable, and how to install it, as well as what should we pay attention to when we use it. FS.COM provides mode conditioning patch cables with various options, from all types of connectors to different jacket and different lengths, such as LC to LC OM3 mode conditioning patch cable, LC to ST OM2 mode conditioning patch cable, or SC to SC OM4 mode conditioning patch cable, etc. Besides, FS.COM also has lots of standard fiber optic patch cables in stock, like SC to SC fiber cable, or LC to FC fiber cable, and so on. All of these patch cables are at high quality and low price. If you need related products, please visit FS.COM or contact sales@fs.com.