The Truth About Single Mode Fiber Types

OS1 and OS2 single mode fibers are the essential communication medium that works by delivering optical signals in extremely pure glass or plastic fiber. However, for the layperson, all fiber cables look like the same, with differences hidden in their dimensions. But if you study deeper, there are countless changes between them, such as the performance, cost and so on. And choosing the right fiber optic cable is also critical. In this post, I’d like to focus on single mode fiber types.

What Is Single Mode Fiber?

Single mode fiber optic cable is a type of fiber optic cable, which features a core diameter of nominally 9µm. This is the most basic difference between single mode and multimode fibers. Due to its small diameter, there’s only one transmission mode of light. Thus, compared with the multimode fiber, single mode fiber prohibits light reflection so that attenuation of signal could be reduced and offers the highest transmission speed. As a result, light in single mode fiber can go further, which means its transmission distance is longer. In addition, the core number of single mode fiber includes 24, 48, 72, 96 and so on. And you can customize the fiber product with the specific core number.

single mode fiber types on patch panel

Figure: Single mode fibers are connected in a patch panel.

Single Mode Fiber Types: OS1 VS OS2

OS1 and OS2 fiber are the two single mode fiber types that are generally well known today.

What Is OS1?

OS1 is an indoor cable that uses the tight buffered cable construction. And this single mode fiber is compliant with all ITU-T G.652 standards including ITU-T G.652A, ITU-T G.652B, ITU-T G.652C, ITU-T G.652D. In general, the maximum attenuation of OS1 can achieve 1.0 dB/km.

What Is OS2?

OS2 is an outdoor loose tube fiber optic cable. It’s widely used in outdoor applications where the cabling process applies no stress to the optical cables. Unlike OS1, OS2 cables just meet the ITU-T G.652C or ITU-T G.652D standards. And the maximum attenuation of OS2 is 0.4 dB/km. Therefore, the maximum transmission distance of OS2 is much longer than that of OS1, and OS2 fiber optic cable price is higher than OS1.

OS1 VS OS2: Differences

The difference between OS1 and OS2 are quite clear. They have different construction, standards, attenuation and transmission distance. As a result, OS1 and OS2 are applied in different applications. OS1 is commonly used in a campus or data center, whereas OS2 is applied in outdoor constructions like the street etc.

How to Choose Single Mode Fiber Types

Knowing single mode fiber types can help us to choose the suitable fiber cable. Transmission distance is always the most important part when buying the cable. Besides, fiber optic cables price is also very critical when making the final choice. When you need fibers for indoors application, choose OS1. And choose OS2 for outdoors uses. However, considering that there’s not a big difference between OS1 and OS2 price and future’s network upgrade, I recommend you choose the OS2 fiber which has better performance. The following is single mode fiber optic cable price comparison between FS.COM and another vendor.

OS2 Types
FS Price(USD)
LC to LC Duplex (1m)
LC to SC Duplex (1m)
SC to SC Duplex (1m)
LC to LC Simplex (1m)
LC to SC Simplex (1m)
SC to SC Simplex (1m)

We can see, FS.COM offers OS2 fibers with reasonable price and good quality.


OS1 and OS2 are the two single mode fiber types used in telecommunication infrastructure. When you decide to buy single mode fiber cables, consider the transmission distance and price based on your actual need. FS.COM offers you fiber products with good quality and favorable price. For further information on optical fiber products, please contact us via

The Selling Price Of Fiber Optic Cable

In general, fiber optics cost from 1 to 5 percent more than standard copper wire and multimode fiber sells at a higher price than single-mode fiber.

Although single-mode fiber is by far the predominant fiber for telecommunications, multimode is used in short-reach applications, including for data centers and some other local area networking deployments, as well as for numerous specialized applications not for telecom, such as medical uses, imaging and some illumination.

Multimode is not cheaper than single-mode fiber. However, the inexpensive LEDs or vertical-cavity surface-emitting lasers (VCSELs) and detectors used to power it are generally less expensive than its single-mode fiber counterparts. The real growth potential is in data centers using VCSELs with multimode fiber. Optical component vendors that can use VCSELs to carry signals in duplex or multistrand multimode fibers may find a market in local area networks or the growing number of data centers throughout the world. Short-range links would appear to be perfect for multimode fibers.

Although konw multimode fiber is more expensive than single mode fiber, what are the other factors deciding the fiber optic cable price?

Fiber optic cable prices are different based on the different cable types, even for the same structure fiber optic cables, the prices may be different because of the different fiber counts, jackettypes, lengths, etc.

The cable design influences the cost of a fiber optic cable. A simple duct cable will be less priced than a direct buried cable, which needs extra protection to meet additional mechanical and environmental safety when the cable is used for direct buried application. A self-supporting type aerial cable may be more expensive than a duct and direct buried type cables. The number of sheaths affects the cost. The more the number of sheathing layers, the higher the cost of cable will be. Process cost and material cost increases drastically proportional to the number of sheathing layers.

It is not always the construction of a cable that decides the cost of a fiber optic cable. The quantity required and delivery also plays major role in the costing of a fiber optic cable. A more quantity, cable manufacturers will offer a cheaper price. When buying a fiber optic cable from fiber optic cable manufacturer, most probably if we approach a cable manufacturer with a requirement of fiber optic cable, they will ask the quantity and delivery time at first apart from the construction requirements.

Fiber optic cable prices from different fiber optic cable manufacturers are also not same, sometimes they may be quite different, even you are asking about the same structure cable, this may be because of the quality, but brand names may also affect the fiber cable prices.

As you know, Corning developed the first commercial optical fiber in 1970. Corning and OFS remain the No. 1 and No. 2 fiber optic cable makers in the world currently. Corning and OFS almost control every aspect of the optical fiber-making process, including extruding the glass from draw towers, doping it, cooling it, stringing it, testing it, marking it, and then either cabling it or shipping it to other cablers.

Another hidden factor influences fiber optic cable price is the market. If the demand is more and competitors are less, the price will be naturally higher.

FAQs Before Buying Fiber Optic Cable

Fiber optic cable is a large, long-distance optical signal transmission unit, by means of which we can spread out the various optical signals with low attenuation rate to meet signals transmission needs between different fields. There are more than 15.000 varieties of fiber optic cables in the telecommunication field. Choosing the right fiber optic cable is extremely important for any installation. Purpose of the cable is to protect the fibers during installation and the service lifetime. This article is written to address your concerns regarding what types of fibers do you need, where they will be installed, and where to buy fiber optic cable.

fiber optic cable

What Types of Optical Fiber Should I Choose and How Many Fibers?

It may be familiar for you that optical fibers are divided into two different mode which is multimode and single mode.

Single mode fiber has a core that is 8.3 microns in diameter. Single-mode fiber requires laser technology for sending and receiving data. With a laser used, light in a single mode fiber also refracts off the fiber cladding. Single-mode has the ability to carry a signal for mile, making it ideal for telephone and cable television on providers.

Multimode fiber, as the name suggests, permits the signals to travel in multiple modes, or pathways, along the insides of the glass strand or core. It is available with fiber core diameters of 62.5 and a slightly smaller 50 micron. 62.5 micron multimode is referred to as OM1. 50-micron fiber is referred to as OM2, OM3, and the recently added OM4. OM4 has greater bandwidth than OM3 and OM3 has greater bandwidth than OM2.

While single mode fiber has a core that is 8.3 microns in diameter. Single-mode fiber requires laser technology for sending and receiving data. With a laser used, light in a single-mode fiber also refracts off the fiber cladding. Single-mode has the ability to carry a signal for mile, making it ideal for telephone and cable television on providers. 50-micron OM3 fiber is designed to accommodate 10 Gigabit Ethernet up to 300 meters, and OM4 can accommodate it up to 550 meters. Therefore, OM3 and OM4 fiber are always chosen over the other glass types. In fact, nearly 80% of 50-micro fiber sold is OM3 or OM4

Except for the fiber mode, the number of fibers is necessary to know. Usually, unless you are making patch cords or hooking up a simple link with two fiber, it is highly recommended that you include a number of spare fibers. Corporate network backbones are often 48 fibers or more. Most backbone cables are hybrids – a mix of 62.5/125 multimode fiber for today’s networks and single-mode fiber for future networks. If the slowest network planned today is as gigabit speeds, it might even be better to use the new 50/125 multimode fiber optimized for the laser sources used in gigabit networks.

Where to Install the Fiber Optic Cable? Indoor, Outdoor or Both?

Outdoor cables are designed to protect the fibers from years of exposure to moisture. Until recently, your only choice for outdoor cables was loose-tube, gel-filled cables. But now you can buy dry water-blocked cables similar to indoor designs that are easy to terminate without breakout kits, saving incredible amounts of time. In a campus environment, you can even get cables with two jackets: an outer PE jacket that withstands moisture and an inner PVC jacket that is UL-rated for fire retardancy. You can bring the cable into a building, strip off the PE jacket and run it anywhere, while normal outdoor cables are limited to 50 feet inside the building.

Indoor cables are what we called “tight-buffered” cables, where the glass fiber has a primary coating and secondary buffer coatings that enlarge each fiber to 900 microns – about 1 mm or 1/25- inch- to make the fiber easier to work with. These cables can be directly terminated.

The most popular cable for indoor use is distribution cable, which has a number of 900-micron buffered, color-coded fibers inside a single jacket. It’s the smallest and lightest cable, and each fiber is sturdy enough for direct termination. Another choice for indoor use is the breakout cable, which is just a bunch of simplex cables inside a common jacket for convenience in pulling and ruggedness.

Where to Buy Fiber Optic Cable?

Once knowing what kind of fiber optic cables is needed, last but not least is to decide where to buy your required fiber optic cables. In the actual production of fiber optic cable, materials which are wearable, radiation proof and adaptable to temperature is very important. Good core material and the external packages. When buying fiber optic cable, qualification of the fiber optic cable manufacturers should be taken into consideration, choosing qualified and professional manufacturers will ensure you quickly get the problem resolved after the sale.