Introduction to 1000BASE-LX/LH SFP Transceiver

There are many types of transceivers to support different types of fiber connections. Which transceiver is the right one for your application? The answer largely depends on how far your connections need to travel. When looking at transceiver model numbers, you'll see one of the following: T, SX, LX, LX/LH/LR/LR+, CX4, ER/ER+, or ZX. Each transceiver has different compatibility of fiber and copper mode types. Among them, 1000BASE-LX/LH SFP is one popular optical transceiver type in optical transmission systems. And this article will talk about it.

What Is 1000BASE-LX/LH?

1000BASE-LX10 was standardized six years after the initial gigabit fiber versions as part of the Ethernet in the First Mile task group. It is very similar to 1000BASE-LX, but achieves longer distances up to 10 km over a pair of single-mode fiber due to higher quality optics. 1000BASE-LX is specified to work over a distance of up to 5 km over 10 µm single-mode fiber, and all common types of multi-mode fiber with a maximum segment length of 550 m. Before it was standardized 1000BASE-LX10 was essentially already in widespread use by many vendors as a proprietary extension called either 1000BASE-LX/LH or 1000BASE-LH. Thus, we often see 1000BASE-LX/LH rather than 1000BASE-LX10. LX/LH stands for "long wavelength/long haul". Unlike the SX, MMF will only be able to span 550m regardless of the cable's core size. SMF is able to travel up to 10km but runs around 5km are typical using standard single-mode patches. LX is often used when networking a campus and LH can be used for runs across town to the local Internet service provider (ISP). LH purely uses SMF. If you are laying shorter spans of SMF, you should consider using in-line attenuators.

1000BASE-LX/LH SFP Transceiver Module

1000BASE-LX/LH SFP transceiver module is similar with the other SFP transceivers in basic working principle and size. The transceiver consists of three sections: a FP laser transmitter, a PIN photodiode integrated with a trans-impedance preamplifier (TIA) and MCU control unit. As we know, fiber comes in two modes, multi-mode fiber (MMF) and single-mode fiber (SMF). An optical transceiver module is generally either made for single-mode (long distance) or multi-mode (short distance). But 1000BASE-LX/LH SFP can be used for both single-mode and multi-mode. 1000BASE-LX/LH SFP transceiver is a high performance 1310nm transceiver for single-mode fibers. It is compatible with the IEEE 802.3z 1000BASE-LX standard and also supports dual data-rate of 1.25 Gbps/1.0625 Gbps with a transmission distance of 10 /15 /20 km. It has three part numbers: SFP-1G31-10-xx, SFP-1G31-15-xx and SFP-1G31-20-xx. 1000BASE-LX/LH SFP transceiver is commonly applied for Gigabit Ethernet links, Fiber Channel Switch Infrastructure and other optical transmission systems. The following picture shows a 1000BASE-LX/LH SFP transceiver module.

In a word, 1000BASE-LX/LH SFP has two identities. It is single-mode by design, but when it gets together with its friend "mode conditioning patch cable", it can also be used for multi-mode application. This patch cable inserts a single to multi-splice on the transmit path, to "fill" the multi-mode fiber with light. It is more expensive than normal patch cables, but is necessary if using these on multi-mode fiber. At present, 1000BASE-LX/LH SFP is the only one kind of fiber optic transceivers which can be used for both single-mode and multi-mode applications. And these applications are depending on what fiber you use.

Fiberstore offers a large amount of in-stock 1000BASE-LX/LH SFP transceivers and 1000BASE-LX SFP transceivers which are compatible for Cisco, Juniper, Dell, Finisar, Brocade, or Netgear in various options. For example, Cisco GLC-LH-SM 1000BASE-LX/LH SFP transceivers are high performance and cost-effective modules supporting dual data-rate of 1.25Gbps/1.0625Gbps and 10km transmission distance with SMF; and Juniper EX-SFP-1GE-LX 1000BASE-LX SFP is fully compatible with Juniper devices.