Access PON using downstream 1550-nm WDM routing and upstream 1300-nm SCMA combining through a fiber-grating router

We describe an 8-channel access passive optical network using a fiber grating router at the remote node, 50 Mb/s 1550-nm WDM downstream transmission from an integrated multifrequency laser, and 3 Mb/s 1300 nm SCMA upstream transmission. This approach combines the advantages of a downstream WDM PON and an upstream low-cost power-combining PON.