Increasing upstream capacity in TDM-PON with multiple-wavelength transmission using Fabry-Perot laser diodes

We propose a new technique for multiple-wavelength upstream transmission in time division multiplexed-passive optical networks using Fabry-Perot laser diodes (FP-LD) at optical network units (ONU). The FP-LD transmits at one of strategically separated seeding wavelengths from the optical line terminal enabling the ONUs to join one of few TDM upstream channels. The scheme increases upstream capacity without the use of costly, higher speed burst mode transceivers. We present experimental results showing that up to 9 upstream channels at 2.5 Gb/s data rate can be achieved with this scheme. The paper presents locking characteristics of the FP-LD relevant for this application such as suppression of other seeding wavelengths, minimum wavelength separation and burst mode operation.