The main components of the fiber optic connector and analysis of the domestic situation

An optical fiber connector is a device that is detachably (actively) connected between an optical fiber and an optical fiber. It precisely butt-joins two optical fiber ends so that the optical energy output from the transmitting optical fiber can be coupled to the receiving optical fiber to the utmost extent. It also minimizes the impact on the system due to its involvement in the optical link, which is a basic requirement for fiber optic connectors. To a certain extent, fiber optic connectors affect the reliability and performance of optical transmission systems.

Fiber optic connectors are unique. Fiber optic cables send light pulses, not electrical signals, so the termination must be more accurate. Instead of merely allowing the pins to make metal-to-metal contact, in order to allow communication, the fiber optic connector must be perfectly aligned with the microscope glass. Although there are many types of types, they have similar design features.

Double fiber and single fiber:

Single fiber refers to one connector per port

However, dual fiber refers to two connectors per port

The three main components of fiber optic connectors: metal rings, connector bodies, and coupling mechanisms.

Metal ring - This is a thin structure (usually cylindrical), which actually holds the glass fiber. There is a hollow center on the fiber to form a tight handle. Metal rings are usually made of ceramics, metals, or high-quality plastics, and usually will hold one strand of fiber.

Connector body - This is a plastic or metal structure that retains the ferrule and attaches to the sheath and the reinforcing cable itself.

Coupling mechanism - This is the part of the connector body that is used to secure the connector when it is connected to another device (switches, network cards, bulkhead couplers, etc.). It may be a latch clip, bayonet nut, or similar device.

The optical fiber connector:

Common fiber connector types:

SC was developed by the Japanese Telegraph and Telephone Company (NTT) laboratory in the mid-eighties and is one of the first connectors to enter the market with the arrival of ceramic ferrules. The SC, sometimes referred to as a "plaza connector" has a push-pull coupling end face with a spring-loaded ceramic ferrule. Originally used for Gigabit Ethernet networks, it was standardized in 1991 as a telecommunications standard TIA-568A due to The cost has come down, and popularity has grown slowly, and because of its outstanding performance, it occupies optical fiber for more than ten years and is only comparable to ST. For thirty years, it is still the second most common connector for polarization maintaining applications. Ideal for data communications And telecom applications, including point-to-point and passive optical networks.

Some people believe that it is a modern replacement SC connector; its launch was not successful, in part because of the initial high licensing fees from the inventor Lucent. Push-pull connectors, where the LC utilizes a latch relative to the SC and has a smaller ferrule, it is called a latch of a small form factor connector. Having half the footprint of the SC connector makes it extremely popular in data communications and high density patches. The combination of its small size and latching capabilities makes it ideal for densely populated racks/panels.

With the introduction of LC-compatible transceivers and active network components, its steady growth in FTTH may continue.

FC is the first fiber optic connector to use a ceramic ferrule, but unlike plastics SC and LC, it utilizes a round spiral type fitting made of nickel or stainless steel. The connector end face relies on the proper insertion of the positioning latch and is then screwed into the adapter/jack of the threaded collet. Despite the extra complexity in installation and installation, it is still the preferred connector for precision measurement devices such as OTDR products.

Originally used for data communications and telecommunication applications, its use from the launch of SC and LC has decreased. These provide similar performance to the FC but both have less expensive components and connect faster. However, the FC clip on the screw does not make it particularly effective in high vibration environments, ensuring that the spring-loaded ferrule is firmly fitted.

Shortly after FC arrived, the ST connector was developed by AT&T. At a glance it can be misdiagnosed as each other and ST uses a bayonet fitting instead of a thread. Use has declined in recent decades, with FC for the same reason. In addition, it cannot be polished with angles, which limits the use of single-mode fiber and FTTH applications.

The optical fiber connector

It is the most common network environment in which multimode data communications are deployed, such as campus, enterprise networks, and military applications that have their advantages at the time of the quick connect bays. It is usually installed to the infrastructure built at the turn of the century. When it comes to retrofitting, the costs are usually swapped out more cost-effectively.

At present, with the continuous development of the domestic telecommunication business, optical fiber communication has entered the stage of practical application, and the scope of application is more and more extensive. China now uses fiber optic connectors used in optical communication systems, either using imported connectors, or assembling so-called “parts” such as imported ceramic ferrules and peripheral metal parts, or according to imported foreign technologies. And key equipment for production, mainly FC-type fiber optic connectors. In view of this situation, the author proposes the following.

Internationally, there are many models and standards for optical fiber connector products. If they are not limited when they are introduced and used, they will inevitably create confusion and inconvenience for maintenance and management. According to reports, the United States, Japan, Germany, France, and other countries have national standards and are recognized by the IEC; China has similar provisions in this regard. It is recommended that such provisions be published as a national standard as part of technical documents such as technical specifications or network access requirements.

Since communication is a system project, it is recommended that users should consider the compatibility of optical connectors used in optical transmission equipment, optical accessory equipment, and optical test instruments when ordering. On the basis of not affecting the performance of the system, the model of the instrument to be ordered and the connector of the instrument of the existing instrument should be consistent as much as possible. If not, you should consider the problems that may occur during use, and order or prepare the appropriate adapter flange or adapter cable.

As far as production is concerned, it is recommended that the state guide the development of manufacturers of fiber optic connectors based on relevant regulations, combined with existing domestic and operational conditions, and develop them based on a core component (such as φ2.5mm pins and corresponding sleeves). Develop products that meet national conditions and adapt to needs.

In terms of use, it is recommended that the user select the applicable fiber optic connector according to his actual situation. Under the premise of meeting system requirements, full consideration is given to the relationship between performance, price, and development, and efforts are made to reduce costs and expand the scope of use. In the future of fiber-optic user networks and high-speed LANs, issues such as price and hardware upgrades may become more prominent, and users need to comprehensively consider performance, price, and development.