Coherent optical video distribution system using shared local oscillator configuration

Coherent subcarrier multiplexed (SCM) systems for broadband fiber-optic video distribution networks are considered. A specific architecture is discussed enabling both the transmitter and local oscillator (LO) laser to be shared among multiple optoelectronic receivers. It is shown that the system performance can be greatly enhanced by inserting an inline optical amplifier. A consequence of this system architecture is that the shared LO cannot be used for optical tuning. However, this design can be employed for video distribution in a fiber-to-the-curb architecture or as a video feeder network connecting the central office to multiple distribution hubs, where optical tuning is not an issue. Measurements with an optical amplifier demonstrated transmission of 48 FM-channels with the LO being shared among eight subscribers. The analysis of the coherent SCM system showed that a significant increase in the number of subscribers can be obtained when an inline optical amplifier is used. >