When we choose OTDR or Power Meter, we usually need to choose the right connector type.
What is Fiber Optic Connector?
Fiber optic connector, or optical fiber connector, is a component that terminates the end of a fiber optic cable and enables faster connection and disconnection than fiber splicing. It mechanically couples and aligns the fiber cores to make light pass successfully. Therefore, fiber optic connectors have an important impact on fiber optic transmission reliability and system performance.Generally speaking, high-quality optical connectors lose very little light due to reflection or misalignment of the fibers.
Generally speaking, the connector type is: SC.LC.FC. ST.
SC connector was one of the first connectors to hit the market following the advent of ceramic ferrules. Sometimes referred to as the "square connector", SC connector uses a push-pull latching mechanism. It has a larger connector housing and a larger 2.5mm ferrule.
LC connector was less successful, partly because of the initially high license fees from inventor Lucent Corporation. The LC uses a latch as opposed to the SC locking tab.It has a smaller connector housing and a smaller 1.25mm ferrule.It is very popular in datacoms and other high-density patch applications.
The FC connector is a fiber-optic connector with a threaded body, designed for use in high-vibration environments.It is commonly used with both single-mode optical fiber and polarization-maintaining optical fiber.
ST stands for Straight Tip - a quick rlease bayonet-style connector developed by AT & T.. ST Connectors are among the most commonly used fiber optic connectors in networking applications. They are cylindrical with twist lock coupling, 2.5mm keyed ferrule.
What is UPC and APC?
There are four types of connector ferrule polishing style in all. UPC and APC are two types of them. UPC stands for Ultra Physical Contact, APC stands for Angle Polished Connector. The main difference between UPC and APC connectors is the fiber end.UPC connectors are polished with no angle. Upc connectors are not exactly flat. However, they have a slight curvature for better core alignment. But APC connectors have a fiber end face that is polished at an 8-degree angle.With UPC connectors, any reflected light is reflected straight back to the light source.However, the angled end face of the APC connector causes reflected light to reflect into the cladding at an angle rather than straight back to the source.
Differences between UPC and APC Connector
This causes some differences in return loss. Therefore, the return loss of the UPC connector is usually required to be at least -50dB or higher, while the return loss of the APC connector should be -60dB or higher.In general, the higher the return loss, the better the performance of the mating of two connectors. In addition to the fiber end, another more obvious difference is the color.Generally, UPC connectors are blue, while APC connectors are green.The following figure shows the differences mentioned above intuitively.
Application considerations of UPC and APC Connectors
In the current market, the APC connectors are widely used in applications such as FTTx, passive optical network (PON) and wavelength-division multiplexing (WDM) that are more sensitive to return loss. For applications that require high-precision optical fiber signaling, APC should be the first consideration, but less sensitive digital systems will perform equally well using UPC.
Splicermarket has a full series of fiber testing instruments with different connectors available.Contact the sales to pick the suitable one for you.