Introduce OS2 Single Mode Fiber

cable construction, optical fiber cables, single mode fibers, maximum transmission distance, coarse wavelength division multiplexing, low water peak fibers, os1 vs os2
Figure: ST/FC/LC/SC fiber optic cable

As we know, OM1, OM2, OM3, and OM4 are defined for multimode fiber. What about single mode? Typically, single-mode fiber is classified into OS1 and OS2. OS1 and OS2 are standards (specifications) for single-mode fiber optic cable. There are actually quite a few differences between an OS1-compliant cable and an OS2-compliant cable. So, here let’s know more about os2 fiber.

What Is Single Mode Optical Fiber?

Single Mode Fiber is also called Less Reflection Mode, because the diameter of its core is very less, due to which data is transmitted by a single ray of light. In this, having less reflection than other modes, the data is able to travel for a long distance, and at the same time, the amount of data loss is also very less.

Single-mode optical fiber can have a diameter in the range of 7-9 microns, depending on the type. The normalized parameter for single-mode optical fibers is the mode spot diameter, the value of which depends on the type of optical fiber and the operating wavelength and lies within 8-10 microns.

In accordance with the international standard ITU-T Rec. G. 652, the deviation of the mode spot diameter from its average value is not more than 10%.

LC UPC to LC UPC Duplex fiber optic cable
Figure: LC UPC to LC UPC Duplex fiber optic cable

What is os2 smf fiber?

The regulatory requirements for class OS2 single-mode optical fibers are specified in ITU-T G.652C and G.652D. Engineers were primarily interested in the 1360-1460 nm range – the attenuation peak was in this region.

But after they managed to get rid of it, it turned out that even a wider window, from about 1280 to 1625 nm, became technologically applicable.

By the way, do not be surprised if in some materials you find ranges from 1310 to 1625 nm, from 1270 to 1620 nm, or other combinations of values ​​- developments in this area are ongoing, the numbers may still be corrected. An example is data for OS2 singlemode cables offered by Siemon:

As you can see, the attenuation in Siemon single-mode OS2 cables is not only less than 0.4 dB / km, but in some areas, it is also lower than 0.3 dB / km.

In fact, many manufacturers already had fibers with such characteristics even before the official adoption of the requirements for OS2, but according to the standard, they could only be applied to the OS1 designation that was officially valid at that time.

As a designer and user, you will find the following table of distance limits to guarantee the performance of various network applications. The gigabit application is highlighted.

How OS2 Fiber works?

A laser infuses a high-data transmission single mode fiber-optic link with the light of a thin unearthly width. A long strand of glass fiber commonly spreads laser transmission with the utilization of wave division multiplexing (WDM), which divides announces various frequencies to build the transmission motion.

This further develops the transmission pace of single-mode over multimode fiber, up to multiple times the possible distance.

The single light wave in the tight center essentially kills mutilations from obstruction or loss of light. This creates the most elevated transmission speed from transmitter to beneficiary of any fiber.

It works paying little mind to electromagnetic obstruction (EMI) and limits snooping by taking out signal spillage. Light frequencies around 1,300 nm serve for brief distances and 1,500 nm serve significant distances.

A communicating laser diode conveys a light message down a solitary mode fiber-optic link. Light, unfit to stop, ricochet, departure, or turn around through a line of somewhat bigger breadth, such as ping pong balls, goes ahead through a center encompassed by a non-permeable cladding that is multiple times as thick.

The frequency moves consistently with the powerlessness to refract, reflect or disperse as hotness inside the wave. It has no place else to go, with the exception of assuming that it experiences exemplified fabricating imperfections or establishment or interfacing mistakes.

Signal heartbeats can go through regenerative or attenuators until they arrive at a beneficiary. There, a photodiode interprets the waveforms roughly 8,000 times each second, changing over them into electronic PC signals as computerized information and sound/video data.

It resembles perusing a whole 24-volume set of reference books in a single second.

In single-mode fiber-optic link, this type of low-misfortune, least request engendering can just work over a specific cutoff frequency.

This is known as the single-mode (SM) step-list. This implies that main the straight light pillar is chosen for single-mode transmission;

They don’t cross or skip at various rates in multimode wave proliferation, through the expansive center of the multimode fiber.

Various sorts of single-mode fiber-optic links incorporate cutoff or scattering moved fiber, non-zero scattering moved low water top fiber, and others. Otherwise called mono-mode or uni-mode fiber, it is fundamentally utilized for wide region organizations (WANs);

However, it has drawn in more consideration than neighborhood (LANs), which stretch out their range to more prominent distances in settings like a college or corporate grounds.

These significant expense links have restricting variables like bowing sweep, so cautious arranging ought to be done preceding establishment by a gifted professional.


Single-mode fiber optics cable is used for long distances, because the diameter of the glass fiber core is very small, due to which a single beam of light passes through and through which it travels a long distance.

The bandwidth of SMF cable is also higher than multi mode fiber optics, and the laser is used in it.

Single-mode fiber is more expensive because it requires precise calculations to pass the laser through a small space.


High Bandwidth:

The data transmission speed of optical fiber is much higher than that of copper cable, due to which a large amount of data is transmitted in a very short time.


Optical fiber is more secure than metal cable, because it has more security layers, and data is also transferred in the form of light. Due to which it is not so easy to tamper with the data, that is, it is a more secure way of data transmission.

Low Power Loss:

Power loss in optical fiber is negligible, due to which data is transmitted over long distances, and the speed of data also remains the same.

Electronic Isolation:

There is no risk of electrical short circuits in optical fiber as compared to copper cable because its parts are made of silica glass and plastic, which keeps it away from electrical hazards.


Expensive Cost:

Optical fiber cable is more expensive than metal cable, and the equipment used in its connection is also expensive compared to others.

Splicing Issue:

If ever a joint is to be installed or repaired between the wires, then it becomes very difficult, and for this Splicing Machine is used.

Expensive Installation:

Along with the equipment of optical fiber, its installation is also very expensive, and it requires trained people.