G.652.D vs G.657.A1 vs G.657.A2: What’s the Difference?

ITU-T (International Telecommunication Union) defines several single-mode fiber standards, including G.652, G.653, G.654, G.655, G.656, and G.657. Among these, commonly used standards are G.652.D, G.657.A1, and G.657.A2. This article intends to provide a clear explanation of G.652.D vs G.657.A1 vs G.657.A2 fiber optic cables and highlight their key distinctions. For more information on ITU-T standards for single-mode optical fibers, please refer to our article Understanding ITU-T Standards for Optical Fibers.

What's G.652.D Fiber?

G.652 fiber is widely recognized as the most commonly used single-mode fiber. It can be categorized into four subtypes: G.652.A, G.652.B, G.652.C, and G.652.D. All four variants share a core size of 8-10 microns. Notably, the performance of G.652.C and G.652.D optical fibers surpasses that of G.652.A and G.652.B.

Both G.652.A and G.652.B are designed with a zero dispersion wavelength point at 1310 nm, making them well-suited for operations within the 1310 nm band. However, they are not suitable for wavelength division multiplexing (WDM) due to the water peaks nature. On the other hand, G.652.C and G.652.D are enhanced versions that eliminate the water peaks, allowing for optimal performance in the 1310 to 1550 nm wavelength range. This enables support for coarse wavelength division multiplexing (CWDM). Compared to G.652.C, G.652.D exhibits superior PMD (Polarization Mode Dispersion) parameters. Therefore, G.652.D is referred to as Standard Single-Mode Fiber (SSMF). The following diagram illustrates the differences between G.652.D and traditional G.652 fibers.

What's G.657 Fiber?

As the demand for higher fiber densities, network professionals seek single-mode fiber that can operate in more confined areas with tighter cable routing and smaller bend radii.

In such scenarios, single-mode fiber compliant with the G.657 standard is necessary. Cables meeting this standard are commonly referred to as Bend Insensitive (BI) or Reduced Bend Sensitive (RBS) fiber optic cables. G.657.A1 fiber cables and G.657.A2 fiber optic cables are subcategories within the G.657 standard, with G.657.A1 having a bending radius of 10mm and G.657.A2 having a bending radius of 7.5mm.

G.652.D vs G.657.A1 vs G.657.A2

Similarity

G.652.D, G.657.A1, and G.657.A2 fiber optic cables all share the same physical dimensions, with inner and outer core diameters of 9μm and 125μm respectively. This means that cables defined by these three standards are fully compatible with each other.

Difference - Bending Radius

The diagram below illustrates the different bending radius standards for G.652.D, G.657.A1, and G.657.A2. The bending radius for G.652.D fiber is 30mm, for G.652.A1 fiber is 10mm, and for G.652.A2 fiber optic cable is 7.5mm. It is worth noting that the attenuation of G.657.A1 and G.657.A2 fiber optic cables will be slightly higher than that of G.652.D fiber. This is because when the optical fiber is bent, the path of the optical signal inside the fiber changes, resulting in increased signal loss.

Application

Regarding their usage, G.652.D fiber cable is ideal for:

• Network and communication LAN applications

• Coarse wavelength division transmission in metropolitan area networks and access networks

• Indoor/outdoor fiber optic networks

On the other hand, G.657.A1/A2 fiber is ideal for:

• Installation in tight spaces due to its increased flexibility

• Cabinets, enclosures, and racks with limited space requirements

The table below provides a comparison of the bending characteristics and attenuation between G.652.D, G.652.A1, and G.652.A2 fibers.

FS High-Performance Solutions for Bend-Insensitive Fiber

FS offers high-quality and comprehensive fiber optic solutions, encompassing bend-insensitive fibers compliant with multiple standards such as G.652.D, G.657.A1, and G.657.A2. Whether you require G.652.D single-mode fibers for long-distance transmission or G.657 fibers with smaller bend radii for limited spaces, we have the right products to meet your needs.

Below is a table showcasing the reference price and important parameters of our 2m LC to LC bend-insensitive fiber cables complying with G.657.A1 and G.657.A2 standards:

By offering a comprehensive range of single-mode fiber options, FS empowers customers to select the most suitable fiber solution for their specific needs. We strive to deliver top-notch fiber optic products that enable efficient and seamless communication. Seize the opportunity to register now for a personalized solution design consultation. Transform your network with FS today.