An MPO (Multi-fiber Push On) fiber optic patch cable consists of a connector and fiber optic cable, and is a high-density fiber optic transmission patch cable. The MPO connector, part of the MT series connector family, is a multi-core, multi-channel, pluggable connector. The MT series ferrules utilize two 0.7mm diameter guide holes on the left and right sides of the ferrule end face, which connect to guide pins (also called pins) for precise connection.

Compared to other connectors, the MPO connector's key features are its compact design and high fiber count. While the MPO connector has the same dimensions as the SC connector, it can accommodate 12 or 24 fibers, significantly saving cabinet cabling space. Currently, MPO connectors are available in 8-, 12-, 24-, 48-, 72-, and 144-fiber counts, with 12- and 24-fiber MPO patch cables being the most common. 40G MPO-MPO fiber optic patch cables typically utilize 12-fiber MPO multimode ferrules, while 100G MPO-MPO fiber optic patch cables typically utilize 24-fiber MPO ferrules.

The MPO fiber optic connector consists of an optical fiber, jacket, coupling assembly, ferrule, pins, dust cap, and more. The pins are available in both male and female versions. The male connector has two pins, while the female connector does not. The connection between MPO connectors is precisely aligned using pins. When mating the connectors, a spring at the end of the ferrule pushes the ferrule, locking it into place with the adapter. One side of the connector body has a "key," either concave or convex, that controls the relative position of the connectors, i.e., P1, P2, and so on. A marking called a "white dot" on the connector body designates the insertion side of the connector.

Generally, an optical link requires two optical fibers to complete the entire transmission process. Polarity refers to the interconnection matching between the transmitter (Tx) and receiver (Rx) ends of the optical fiber link.

Three types of MPO polarity classifications:

Type A (straight-through): The fiber cores on both ends of the patch cord are arranged in the same position, that is, 1 on one end corresponds to 1 on the other end, and 12 on one end corresponds to 12 on the other end. The key orientations of the two ends are opposite, with key up corresponding to key down.

Type B (interleaved): The fiber cores on both ends of the patch cord are arranged in opposite positions. That is, 1 on one end corresponds to 12 on the other end, and 12 on one end corresponds to 1 on the other end. The key orientations on both ends are the same, that is, key up corresponds to key up, and key down corresponds to key down.

Type C (staggered pairs): Type C MPO patch cords have adjacent fiber cores interleaved. That is, fiber core 1 at one end corresponds to fiber core 2 at the other end, and fiber core 12 at one end corresponds to fiber core 11 at the other end. The key orientations at both ends are also opposite, with key up corresponding to key down.

Three polarity connection methods use different types of MPO trunk cables. However, all methods require duplex patch cords to establish a fiber link. TIA standards also define two different types of LC or SC duplex fiber patch cords for completing end-to-end duplex connections: Type A-A (crossover) and Type A-B (straight-through).