Mode conditioning patch cord is a duplex multi-mode cord that has a small length of single-mode fibre at the start of the transmission length. The basic principle behind the cord is that you launch your laser into the small section of single-mode fibre, then the other end of the single-mode fibre is coupled to multi-mode section of the cable with the core offset from the centre of the multi-mode fibre.
This offset point creates a launch that is similar to typical multi-mode LED launches. By using an offset between the single-mode fibre and the multi-mode fibre, mode conditioning patch cords eliminate DMD and the resulting multiple signals allowing use of 1000BASE-LX over existing multi-mode fibre cable systems. Therefore, these mode conditioning patch cords allow customers an upgrade of their hardware technology without the costly upgrade of their fibre planer