Nonlinear Raman crosstalk in a 125-Mb/s CWDM overlay on a 1310-nm video access network

Repeated idle frames from a 125 Mb/s line-rate fast Ethernet optical link generate a signal with RF spectral content peaked at 62.5 MHz and at its harmonics. We show, experimentally, that this modulation can be transferred from CWDM wavelengths (1430, 1450, 1470 nm...) to an analog video signal at 1310 nm via stimulated Raman crosstalk when the signals are co-propagating. However, no penalty is observed when the signals are counter propagating making CWDM overlay a viable solution to add services on a 1310 video access network.