RF-noise-tone suppression in QPSK transmission with unisolated Fabry-Perot lasers

We have demonstrated a simple, economical method to suppress RF noise tones from subcarrier multiplexed networks that use unisolated Fabry-Perot lasers. This method has no insertion loss. This method will be appropriate for the cost-sensitive upstream transmission of access networks such as hybrid-fiber coax and future SCM all-optical access networks. This method increases the RF input power dynamic range at the transmitting laser by at least 20 dB if an unisolated Fabry-Perot laser is used, and by 1.6 dB compared to the use of a conventionally isolated laser.