What are OS1 and OS2 single-mode fibres?
Both OS1 and OS2 fibres are single-mode optical fibres regulated by the ITU-T standard (i.e., the ITU-T Recommendation, which describes the geometrical properties and transmission characteristics of single-mode and multimode optical fibres). In the ITU-T standard, OS1 single-mode fibre is a conventional single-mode fibre conforming to the G.652.A and G.652B (conventional) fibre standards, while OS2 single-mode fibre is a single-mode fibre conforming to the G.652C and G.652D fibre standards, and is also referred to as low-water-peak fibre or zero-water-peak fibre, which is commonly used in CWDM networks. In addition, the latest G.657A1 fibre standard released by ITU-T specifies a bend-insensitive single-mode fibre with excellent bending resistance.
What is the difference between OS1 and OS2 singlemode fibre?
1. Transmission distance: OS1 is suitable for shorter distance single-mode fibre transmission, its transmission distance is generally around 2 km. OS2 is suitable for longer distance single-mode fibre transmission, and its transmission distance can reach more than 40km.
2. Loss: OS1 loss is more relaxed, generally 0.4 dB/km, while OS2 loss requirements are more stringent, generally 0.25 dB/km.
3. Attenuation: OS1 has a relatively high attenuation limit of 1.0 dB/km, while OS2 has a relatively low attenuation limit of 0.4 dB/km.
4. Centre aperture: OS1 has a centre aperture of 9 μm, while OS2 has a centre aperture of 8.6 μm.
5. Application scenarios: Due to different transmission distances and performance requirements, OS1 is usually used for shorter distance single-mode fibre applications such as data centres, local area networks (LANs), and internal enterprise applications; whereas OS2 is suitable for longer distance single-mode fibre transmission, and is commonly used for applications such as wide area networks (WANs), long-distance communications and long-distance network connections.
In summary, OS1 single-mode fibre is suitable for shorter-distance, conventional single-mode fibre transmission, while OS2 single-mode fibre is suitable for longer-distance, high-performance, single-mode fibre transmission with higher bandwidth and loss requirements. When choosing, you should determine which single-mode fibre specification to use based on your actual needs and budget.