Decoding Grade A Connector in Fiber Optic Patch Cables


With the advances in fiber optic technology and transmission systems, reliable cabling systems are becoming even more important. Active optical equipment, which is often worth hundreds of thousands of dollars, is all connected into the network via the humble fiber optic patch cord or patch lead. The risk of network downtime due to unreliable cabling is one that should be avoided. Therefore, these types of networks, along with many other Data Center and high-speed Commercial networks require reliable cabling infrastructure in order to maximize performance and to ensure long term reliability. Today’s article will introduce Grade A optical fiber cables.

What Are Grade A, Grade B, Grade C Fiber Optic Connectors?
IEC standards dictate the connector performance requirement for each grade of fiber optic patch cord connector. These standards guide end users and manufacturers in ensuring compliance with best practices in optical fiber technology.

According to IEC 61753 and IEC 61300-3-34 Attenuation Random Testing Method, Grade C connectors have the following performance characteristics.
Attenuation: 0.25dB-0.50dB, for >97% of samples.
Return Loss: 35dB

According to IEC, Grade B connectors have the following performance characteristics
Attenuation: 0.12dB-0.25dB, for >97% of samples.
Return Loss: 45dB

Grade A connector performance (which is still yet to be officially ratified by IEC) has the following performance characteristics. Average Insertion loss of 0.07dB (randomly mated IEC Standard 61300-3-34)and a Maximum Insertion Loss of 0.15db max, for >97% of samples.

While the return loss using IEC 61300-3-6 Random Mated Method is >55dB (unmated–only angled connectors) and >60dB (mated), this performance level is generally available for LC, A/SC, SC, and E2000 interfaces.

How are Grade A Connectors on Optical Fiber Patch Cords Identified?
Grade A fiber optic patch cords are identified with the letter ‘A’ printed on the connector side. The symbol is actually the letter ‘A’ enclosed within a triangle (“A”).

This identification marker is proof that you are using a high-quality fiber optic patch cord. Grade A connectivity is also available for Optical fiber through adapters. The same rule applies for A grade fiber optic Adapters which also have the letter “A” clearly marked.

What Does a Fiber Optic Patch Cord Meet the Grade A Criteria?
Firstly a high-quality Grade A fiber optic patch cord begins with using high-quality zirconia ferrules and high-quality optical fiber cable. However, the manufacturing and testing process must be first class.

In order to meet the stringent performance criteria of ‘A’ Grade connectors on patch cords, high-quality manufacturing, inspection, testing, and Quality Assurance (QA) procedures are required. Without the proper expertise in optical fiber technology, many other manufacturers are unable to meet these requirements.

To consistently achieve ‘A’ Grade performance, high accuracy testing using state of the art test equipment as well as constantly assessing testing methods are all required. Analyzing and ensuring mechanical end face limits and that parameters are within range, ensures that Grade A connectivity is achieved.

Grade A connectors offer virtually the same IL performance as a fusion splice, with the added benefit of providing a physical contact which can be connected, disconnected and moved when required.

It is important to fully understand the benefits of using reliable, good quality optic fiber patch cords and connectivity. Good quality connectors with low Insertion Loss will meet large bandwidth and high-speed requirements of the latest active optical equipment allowing large streams of data to be transmitted reliably over long distances. Grade A connectors on optical fiber patch cords are an example of the advances in this technology.


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