Application and test problems of New Optical Fiber Connector (Fluke)

Since the beginning of the year, Gigabit Ethernet based on optical fiber cables has developed rapidly. Almost all of the backbone networks (backbone) in the LAN use fiber-optic Gigabit Ethernet. The connection mode of the optical fiber Link Used in the gigabit network also changes.

1. Traditional optical fiber link connection

The traditional optical fiber link connection modes are ST, SC, or FC connections. They are still in use. Its shape is 1. These optical cables are easy to connect and can be used independently. That is to say, when installing these Optical Fiber Links, you do not know if these optical cables are actually used, that is, you do not know the Signal Transmission Direction of the optical fiber cables. In actual use, when connecting the optical fiber and network equipment, you must first determine the transmission direction of the signal in the optical fiber cable to correctly connect. In addition, it is not convenient to make the connector of the optical cable, and special tools are required.

2. New Optical Fiber Connection Method

We all know that Gigabit Ethernet is used in pairs when connecting optical cables, that is, an output (also a light source), an input (input, optical detector ), for example, the optical fiber connection between a vro and a vswitch. If you can use them in pairs without considering the connection direction, and the connection is simple and convenient, it will be helpful for Gigabit Ethernet connections. Therefore, many cable cabling manufacturers have introduced various connectors to meet this application. This new optical cable connector is called SFF (Small Form Factor ). There are no clear terms to describe. We generally call it a micro-optical cable connector. Currently, there are four main types of SFF optical fiber connectors on the market. LC type, which is an SFF type connector launched by Lucent. FJ type, which is a connector launched by Panduit. MT-RJ type, which is a connector launched by the U. S. AMP and a VF-45 connector launched by 3 M. Are these types of connectors. This connector is connected together with a pair of child optical cables and the direction of the connector is fixed. Therefore
It is easy to use and will not be inserted by mistake.

3. Problem

Using this optical fiber connector to connect to a gigabit network requires that network devices support this connector. If a connector cannot be directly supported, a Optical Fiber adapter is required. In practice, additional losses are added, and the true meaning of using this connector is also lost.

In addition, when testing the loss of Optical Fiber Links using the SFF connector, the optical fiber loss tester uses the traditional ST, SC, and other connection methods, therefore, you need to use a transfer adapter for testing and consider how to exclude the impact of these adapters during testing. Many people may mistakenly think that the loss of a transfer adapter is only a fraction of a point, which does not have a great impact. In fact, it is not. Due to the strict requirements on optical fiber loss in the standard of Gigabit Ethernet, the acceptable margin is very small. In addition, due to the relatively short size of the Gigabit Ethernet Optical Cable, The Impact of connector loss is much greater than that of the optical cable itself. Therefore, the insertion error introduced by the adapter must be ruled out. For example, Fluke networks provided an adapter to test the four Optical Fiber Links and recommended the best test method. The connection diagram of the two optical cables tested using the DSP4000 FTA4X0 optical fiber test adapter. The circle in the figure is the transfer method, and the impact of the transfer adapter is excluded from the final test results. In addition, two optical cables, including the length of the optical cable, can be tested simultaneously.

 

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