Tag Archives: single-mode fiber

Single Mode Fiber Distance

Fiber optic cable is the essential media in telecommunication system for transmitting information. According to different categories, while depending on fiber connectors, patch cable can be considered as LC fiber, FC fiber, SC fiber, ST fiber and so on, it is well known that fiber optic cable can be divided into single mode fiber and multimode fiber based on transmission paths. Today, we will learn more about the single mode fiber distance.

Single Mode Fiber Overview

Single mode fiber derives its name from the fact that it only allows one mode of light to pass through their core at a time. Commonly, single mode fiber is designed with a narrow core diameter of 8 to 10 micrometers, which is much smaller than multimode fiber of 50 or 62.5 micrometers.

Before we continue, we need to be clear that due to different mode of propagation, there is modal dispersion during the signal spreading. And transmission distance is greatly influenced by the dispersion. Luckily, because of the allowance of just one mode of light, single mode fiber have the ability to transmitting data for miles without losing too much data. Thus it can readily carry information for a longer distance than the light used in the multimode fiber.

single mode fiber

OS1 vs OS2

OS1 and OS2 are the two types of single mode fiber, here the term OS refers to optical single mode fiber. Both of them are suitable for Gigabit applications and have the same jacket color.

OS1 cable is indoor tight buffered fiber that is compliant with ITU-T G.652A or ITU-T G.652B standards. The attenuation of this type is 1dB per kilometer with a top transmission distance of 2 km at 10 Gigabit Ethernet. It works between 1310 nm and 1550 nm.

OS2 cable is outdoor loose tube fiber optic cable that comply with ITU-T G.652C and ITU-T G.652D specifications. It has an attenuation of 0.4 dB between 1310 nm and 1550 nm, with a maximum transmission distance of 10 km at 10Gigabit Ethernet.

Selection on Different Distances

Single mode fiber provides a greater transmission distance. When choosing the right fiber cable, the most crucial thing that must be taken into consideration is how far the cable could support. In addition, the transmission distance is also related to the optics that users apply in the equipment.

Technology Bandwidth Wavelength Distance
1000BASE-LX 1000Mbps 1310nm 10km
10GBASE-LR 10Gbps 1310nm 10km
40GBASE-ER4 40Gbps 1310nm 40km
40GBASE-LR4 40Gbps 1310nm 10km

According to the above form, we can clearly see that transmission distance varies greatly. At different transmission rate, the distance changes. Distance of single mode fiber can reach 40km at the speed of 40gigabit Ethernet, and it will be 10km with the speed of 10gigabit Ethernet. Thus, try to buy fiber cable of suitable length for your project based on your network speed and some other actual situations. Thus, try to buy fiber cable of suitable length for your project based on your network speed and some other actual situations.


Transmission distance of single mode fiber is an important factor when people set up a network especially in data center that requires data to deliver over long distances. FS.COM provides a number set of OS1 fiber, OS2 fiber, LC fiber, SC fiber and so on. The products have passed many quality system verification such as CE, FCC. Come and choose your favored cables at FS.COM.

How to Select the Basic Materials of the LAN

Installing or designing network may pose a challenge as there are multiple optical solutions that meet the same specification or requirement. But by understanding the basic optical components and the specific performance requirements, you will be able to generate a cost-efficient bill of materials for your project. Thus before picking any products for your infrastructure, you must read this article.

Fiber Type
There are two basic fiber types: single-mode and multi-mode. Multi-mode fiber is graded by OM (optical multi-mode), the higher the OM grade, the better bandwidth performance you can expect. And it comes in both 50μm and 62.5μm core sizes with 50 μm multi-mode available in both standard (OM2) as well as a laser-optimized version (OM3/OM4). Single-mode are graded by OS (optical single-mode) and can run at OS1 and OS2, as described in TIA-568 C.3. Keep the consistency within your network is critical for long-term performance, therefore you shouldn’t mix new fiber type or performance with your old plant.

single-mode vs.multi-mode fiber transceiver

In addition, the cost of the components should be considered. The transceiver associated with single-mode fiber are more expensive than those for multi-mode. For example, the price of JG661A (compatible HP 40GBASE-LR4/OTU-3 QSFP+ transceiver) is much higher than JG325B (compatible HP 40GBASE-SR4 QSFP+ transceiver). The decision must be made to balance the performance and the cost. Single-mode system will provide for future expansion, yet multi-mode fiber is only for today and the near future. To sum up, single-mode fiber operate better at long reach while multi-mode fiber is ideal for short reach, choosing single-mode or multi-mode depends on your networks needs.

Termination Method
Deciding on a termination methods is typical affected by many factors. If your biggest concern is time, no epoxy/no polish connectors are probably your best choice. The fiber end faces are factory polished and easily installed with a tool kit. This types of termination method allows you to perform terminations quickly, but the cost is usually higher than that of epoxy and polish connector.

If your biggest concern is cost. epoxy and polish connectors might be a good fit because of their low initial price. This type of termination need considerable time to learn how to properly hand-polish connectors that meet specification, and it requires a large workspace to lay out the polishing papers, polishing pucks, epoxy, etc. If your work environment or network condition is not allowed, it is advisable not to select this method.

Fusion Splicer or Optical Connector
Keep in mind that whether to choose fusion splicing or a connector for your network will always need an experienced installer under adequate training. Fusion splicer, as we all know, is very expensive. If your company do not own one, it can be a large investment to make and you need to order the correct splice tray for your hardware and heart-shrinks to keep your splices intact. But if you already have a fusion splicer, fusion-spliced pigtails might be the right choice for you that can provide high quality results and easy to use in areas. The following picture shows a Fujikura FSM-80S Core Alignment Fusion Splicer.

Fujikura FSM-80S Core Alignment Fusion Splicer

Specifications, density, electronics interfaces and existing plant often drive connector choices. LC connector is favored for its maximum density and room-saving. It is also available in duplex from, which allows you to manage polarity by simply reversing the connector via a duplex clip. SC connectors feature an easy push/pull locking mechanism and are available in simplex and duplex forms. ST compatible connectors have a spring-loaded bayonet locking system that helps them stay in place but are only available in simplex versions.

To determine the type of hardware you need, take into consideration the space that will be utilized for the network. If you are installing inside of a closet or other cramped quarters and need low density, wall mountable hardware is the best selection as it does not take up a lot of room. If racks are already in place, or if there is enough room to install them, rack-mount hardware is the best selection because it is sturdy and easy to access.

Rack-mount housing

Additional Information
Designing a network may be a big project as you should take a lot of things into consideration. To make sure the high performance of you network, please think about all the aspects that I have written in this text. What’s more, there are three basic categories for cable: indoor, outdoor and indoor/outdoor. The types of cables you have to choose for your infrastructure depend on where the cables will be run. Fiberstore supplies a whole variety of optical equipment including fiber optical cables, optical transceivers, fusion splicer and optical connectors. Come to us to help your data transmission initiatives for future proof.

Basic Information About Fiber Optic Transceiver

Optical fiber transceivers are also called fiber optic transmitter and receiver, which are used to send and receive optical information in a variety of different applications. The role of the optical module is photoelectric conversion. These optical modules are scalable and flexible in their use, and this is why they are preferred by designers. Here is what you need to know about the basics of fiber optic transceivers.

Fiber Optic Transmitters and Receivers
Fiber optic transmission system consists of a transmitter on one end of a fiber and a receiver on the other end. The transmitter end takes in and converts the electrical signal into light, after the optical fiber transmission in the fiber cable plant, the receiver end again converts the light signal into electrical signal. Both the receiver and the transmitter ends have their own circuitry and can handle transmissions in both directions. Fiber optic cables can both send and receive information. The cables can be made of different fibers, and the information can be transmitted at different times. The following picture shows a fiber optic datalink.

fiber optic datalink

Sources of Fiber Optic Transceiver
There are four types of fiber transmitters used to convert electrical signals into optical signals. These sources of fiber optic transmitters include: distributed feedback (DFB) lasers, fabry-perot (FP) lasers, LEDs, and vertical cavity surface-emitting lasers (VCSELs). They are all semiconductor chips. Take QSFP-40G-UNIV as an example, it is Arista QSFP-40G-UNIV compatible 40G QSFP+ transceiver. It uses DFB lasers as sources for fiber optic transmitters, which are used in long distance and DWDM systems. DFB lasers have the narrowest spectral width which minimizes chromatic dispersion on the longest links.

Arista QSFP-40G-UNIV

The choice of the devices is determined mainly by speed and fiber compatibility issues. As many premises systems using multi-mode fiber have exceeded bit rates of 1 Gb/s, lasers (mostly VCSELs) have replaced LEDs. Fiber optic transceivers are reliable, but they may malfunction or become out-dated. If an upgrade is necessary, there are hot-swappable fiber optic transceivers. These devices make it easy to replace or repair without powering down the device.

How Fiber Optic Transceiver Works?
Information is sent in the form of pulses of the light in the fiber optics. The light pulses have to be converted into electrical ones in order to be utilized by an electronic device. Thanks to the conversion by fiber optic transceivers: In its fiber optic data links, the transmitter converts an electrical signal into an optical signal, which is coupled with a connector and transmitted through a fiber optic cable. The light from the end of the cable is coupled to a receiver, where a detector converts the light back into an electrical signal. Either a light emitting diode (LED) or a laser diode is used as the light source.

Optical fiber transceivers are usually packaged in industry standard packages like SFP, SFP+, XFP, X2, Xenpak, GBIC. According to the fiber type it connects to, there are MM (multi-mode), SM (Single-mode), as well as WDM fiber (CWDM, DWDM modules). The SFP modules support up to 4.25 Gbps with a connector on the optical end and a standard electrical interface on the other end. The QSFP are for 40 Gigabit networks using a LC duplex connection. Take compatible Brocade 40G-QSFP-LR4 as an example, it supports link lengths of 10km on single-mode fiber cable at a wavelength of 1310nm.

Keep in mind that fiber optic transceiver has two ends. One has an optical cable plug and another for connecting an electrical device. Each aspect of the transceivers is necessary to properly deliver a signal to its destination. Be aware of all aspects of fiber optic transceivers to purchase what you need for your application. Fiberstore supplies a wide variety of 40GBASE QSFP+ transceiver modules for you to choose from. More detailed, please contact us directly.