The optical port in the parallel 2 x 4-lane optical transceiver is a male MPO connector with alignment pins, mating with fiber-optic cables with female MPO connector. The connector contains a 12-channel MT ferrule.
QSFP+ Optical Receptacle and Channel Orientation for Male MPO Connector
QSFP+ Optical Lane Assignment (Front View of Male MPO Receptacle)
Female MPO Cable Connector Optical Lane Assignment
Reference: IEC specification IEC 61754-7.
The fiber that connects with the transmitter’s lane 1 must end at receiver lane 1 at the far end of the cable. Position 1 of the MPO connector at the near end of the cable connects to position 12 of the opposite MPO connector. This calls for a crossed MPO cable, which is the standard for MPO patch cables.
The fiber is standard OM3 or OM4 multi-mode fiber. The maximum length is found in the Optical Specifications table.
MPO to MPO Patch Cable Fiber Position
| Left Cord | Connection | Right Cord |
| 1 | ---> | 12 |
| 2 | ---> | 11 |
| 3 | ---> | 10 |
| 4 | ---> | 9 |
| 5 | Not Connected | 8 |
| 6 | Not Connected | 7 |
| 7 | Not Connected | 6 |
| 8 | Not Connected | 5 |
| 9 | <--- | 4 |
| 10 | <--- | 3 |
| 11 | <--- | 2 |
| 12 | <--- | 1 |
Multiple MPO patch cables can be connected in series, but each added connector pair increases modal dispersion in the link which again impairs performance. An odd number of ‘crosses’ must be used between transceivers at the two ends.
Handling and Cleaning
The transceiver can be damaged by exposure to current surges and over voltage events. Take care to restrict exposure to the conditions defined in Absolute Maximum Ratings. Observe normal handling precautions for electrostatic discharge-sensitive devices. The transceiver is shipped with dust caps on both the electrical and the optical port. The cap on the optical port should always be in place when there is no fiber cable connected. The optical connector has a recessed connector surface which is exposed whenever it has no cable nor cap.
Prior to insertion of the fiber cable, clean the cable connector to prevent contamination from it. The dust cap ensures that the optics remain clean during transportation. Standard cleaning tools and methods should be used during installation and service. Liquids must not be applied.