OS1 and OS2, short for Optical Single-mode 1 and Optical Single-mode 2, are fibre optic cable standards. The term single-mode indicates that the fibre optic cable has only one mode of transmission. A single-mode fibre features a single strand that transmits a single ray of light (referred to as the mode).
Another fibre optic cable standard that helps understand the single fibre mode better is the multi-mode fibre, which transmits multiple modes or rays of light simultaneously. Single-mode optic fibre is used for long-distance transmission whereas multi-mode fibre is ideal for transmission over shorter distances.
It is essential to know the difference between OS1 and OS2 so you can choose the right fibre optic cable for your requirements and get the best results for your intended application.
Here are the key differences between OS1 and OS2.
OS1 is used for indoor applications. OS1 cables are common in indoor settings such as campuses, buildings, telecom exchange centres, computer rooms and data centres. An OS1 cable features a tightly-buffered cable construction.
An OS1 cable has a core diameter of 900-microns featuring multiple fibres reinforced with nylon, PVC or Hytrel.
An OS1 optic cable can also be reinforced with an LSZH (Low Smoke Zero Halogen) jacket and aramid yarn – an indoor micro-core 250-micron fibre cable features this technical construction.
In an OS2 cable, the fibres are arranged in a helical manner in semi-rigid tubes. This construction allows the cable, and not the fibre, to stretch. As a result, the fibre is protected from damages caused by stress during cable-laying or due to changes in temperature.
OS1 indoor cables can withstand the stress caused by bending. The fibre material and the tightly-buffered construction prevent any damage that can occur from such bending.
OS2 optic fibre cables are not tolerant of bends. Unless appropriate care is taken, the stress of bending can damage them.
OS1 cables display greater attenuation, meaning greater loss of signal strength than OS2 cables. The maximum attenuation of OS1 fibre cable is 1.0db/km whereas it is only 0.4db/km for OS2 cables.
Given this attenuation, OS1 fibre optic is ideal for distances less than or equal to 2km. OS2 cables can handle a transmission distance of up to 10km (the Ethernet transmission speed in both the cases is between 1 and 10 gigabits).
The greater loss of attenuation is perhaps a reason for the cheaper prices of OS1 cables
Given these differences, it becomes important to specify the type of cable application, location, cable-laying method, transmission distance and the budget, while choosing between OS1 and OS2 cables.
For the best quality in fibre optics, trust Apollo Technology. We are an Australian-owned company specializing in fibre optic cables of standard and customized specifications. Our advanced fibre optic products ensure strong attenuation and seamless communication over networks.
Our product range includes SFP (Small Form-Factor Pluggable) fibre, networking products and testing and measuring equipment.
Call 03 9775 1795 for more information.