Mode Conversion
Mode conversion is accomplished by a device that converts multi-mode fiber operation to single mode fiber operation. This is particularly useful at a customer premise location where the client side of an interface is multi-mode (perhaps an Ethernet circuit) and the network side of that interface utilizes single mode fiber.
The Optelian RGN series of regenerators, with small form-factor pluggable (SFP) optics can convert from multi-mode (electrical or optical) to single mode operation.