Audio and video system fiber optic connector - Hirschman connector
Regarding the fiber optic field supporting audio and video systems, in the past one to two years, we have started to receive more and more inquiries and emails about audio and video fiber optic products. The large number of consultations, * * *. And many of them are related to fiber optic connectors.
In order to support formats such as 4K and 8K, the demand for bandwidth and transmission distance for transmitting audio and video continues to grow. Transmitting an uncompressed ultra high definition 4K video signal requires a bandwidth of 10Gb/s or more.
Due to the fact that copper cables cannot always meet the higher data transmission rates required by technology, designers have turned their attention to fiber optic cables and studied how to use fiber optic cables to provide connection solutions for current and future audio and video formats.
Four basic audio and video fiber optic connectors:
Although there are hundreds of types of fiber optic connectors, the audio and video industry typically uses four types of connectors for termination. (There are also some special types of connectors, but they are usually not used for on-site termination.)
These four types of connectors are available in single-mode and multi-mode fiber options, and will be suitable for the vast majority of audio and video installation work:
1. ST type (direct rotating type): Although this type of traditional connector has disappeared in traditional networks, it still has a place in the broadcasting market. They provide unparalleled robustness compared to other connectors and make the connection points as secure as BNC connectors through locking pins. Its coupling and connector housing module are usually made of metal, making it more robust than some new connectors that use plastic materials. The disadvantage is that in order to meet more reliable audio and video installation, ST type connectors take up a lot of space.
2. SC type (user connector): This type of connector is a convenient push-pull connector, and there are also simplex (one connector) and duplex (two connectors) versions. Installation is very convenient because the vast majority of optical fibers use one fiber to send signals and one fiber to receive signals.
3. LC type (Lucent connector): This type of connector has a release tab similar to an RJ45 plug and has quickly become the most popular LAN connector on the market. Winning the market competition for small package connectors (terminating two connectors in the space of one RJ45 jack), it has become the ideal termination for SFP modules in network switches. With the continuous increase in the number of optical fibers, density has become a problem that needs to be solved, which has enabled these connectors to establish a foothold in the market. This type of connector, like the SC type, also has two versions: simplex and duplex.
4. MPO type (multi fiber push type) connector: Other manufacturers sometimes refer to it as MTP type connector, which increases fiber density to a new level. They have 12 optical fibers in each row. You can stack the fibers in a row so that each connector has 24 to 36 fibers, but it has been proven that stacking is often a laborious and thankless task. MPO connectors are more difficult to perform on-site termination and typically require the fiber to be made into a ribbon. When setting the polarity correctly (connecting the transmitter and receiver), it will be found that its structure is more complex. In addition, they are also one of the few types of fiber optic connectors with male and female pins and angled inserts. Because MPO connectors support simple plug and play cabling systems and provide extremely high bandwidth, they often become the preferred choice.
Use couplers to connect the fibers of the fiber optic connector face-to-face. The connectors listed above have physical contact surfaces between the two ends of the fiber optic cable. Most of these terminals have a small bump to ensure that the center points are in contact with each other. For single-mode connectors, this small bump is commonly referred to as UPC, also known as the "superphysical end face".
Different types of connectors and termination methods will result in different reflections and losses. Have you ever noticed a green connector before? These are APC (inclined physical contact) connectors, which are an exception to UPC; Grind its end face to 8 degrees. The end face does not directly reflect light along the cable, but rather reflects at a certain angle. This type of connector may be crucial in certain AV applications, especially when you are sending and receiving signals in both directions on the same fiber optic cable, which highlights its importance.
Belden offers single-mode LC and SC versions of APC connectors (bright green). Other connector colors include:
·UPC single-mode: blue
·OM1 and OM2 multimode: black and beige
·OM3 and OM4 multimode: line green and purple
·OM5 multimode: lime green
Multiple types of connectors can be used in a project, but we recommend using one type uniformly and adjusting jumpers to meet different device requirements.
For example, if all fibers entering the rack fiber box use SC connectors, but your application facility requires the use of ST connectors, SC-ST jumpers should be purchased at both ends of the fibers
Termination of audio and video fiber optic connectors:
The various types of connectors have been introduced above. Now, let's continue discussing how to terminate connectors at both ends of the fiber optic cable.
There are also four options to choose from here. ***A quick and simple solution is to use factory pre terminated fiber optic cables. This plan installs the connector onto the fiber optic cable and tests the entire link. Because pre terminated optical fibers need to be made according to the specifications you require, you need to know the length in advance. Compared with other solutions, this one has slightly higher costs and longer delivery times.
***The difficult and complex termination method is carving and polishing (I suggest avoiding this method unless you are * * *). This process requires the use of sandpaper to polish the glass end face.
Then there are only two options left: mechanical connectors and fusion connectors. The end faces of these two connectors have been polished before leaving the factory, with very little wear and tear. The mechanical connector firmly clamps both ends of the optical fiber together, and uses the refractive index matching gel for connection. The fusion spliced connector connects the fiber end to the connector or tail fiber end face by melting glass. Fusion spliced connectors have excellent optical performance and temperature stability, so we recommend using such connectors as much as possible.
In addition to these four termination schemes, the AV system industry occasionally uses special fiber optic connectors that need to be adapted in order to be terminated on site.
Neutrik offers a product called OpticalCON ® XLR fiber optic connector. This type of connector is equipped with an LC or MPO plug-in on the board side, allowing for on-site termination. On jumper cables (cables connecting from panels to actual equipment), connectors need to be professionally factory terminated in the assembly workshop.
For the SMPTE 311 connector in the field of broadcast camera applications, it is also too complex to perform on-site termination. Therefore, there are multiple solutions to directly splice this type of connector into your system, or use a board specific on-site termination connector.
With the increasing use of fiber optics, I believe we will see more and more options to choose from. If you are still unsure which connector * * * is suitable, you can call Belden company for consultation. We are very willing to further understand your project and guide you to find the right solution. We can even showcase our FiberExpress fiber fusion splicer, which can be applied to the production of single fiber splice on connectors and tail fiber joints, forming consistent, reliable, and high-quality termination surfaces.
