Title :
A study of optical beat interference between Fabry-Perot lasers
Author :
Woodward, S.L. ; Stayt, J.W., Jr ; Romero, D.M. ; Freund, J.M. ; Przybylek, G.J.
Author_Institution :
Newman Springs Lab., AT&T Labs. Res., Red Bank, NJ, USA
fDate :
5/1/1998 12:00:00 AM
Abstract :
Optical beat interference can be the dominant source of noise in subcarrier-multiplexed (SCM) passive-optical networks (PONs). We have studied how the relative-optical-beat-interference noise (ROBIN) between Fabry-Perot (FP) lasers varies using lasers with both equal, and unequal mode spacing. In our experiments, ROBIN ranged from -96 dB/Hz to -115 dB/Hz. Because the noise level depends on the distribution of optical power in the lasers´ modes, using lasers with different mode spacing led to a 4-dB improvement over using lasers with equal mode spacing. The noise is also correlated with the linewidth of the interfering modes. Broadening these modes by driving the lasers below threshold lowered the noise by an additional 10 dB.
Keywords :
laser modes; laser noise; optical correlation; optical fibre communication; optical transmitters; quantum well lasers; spectral line breadth; subcarrier multiplexing; Fabry-Perot lasers; MQW lasers; below threshold; dominant laser noise source; equal mode spacing; interfering modes; linewidth; mode spacing; noise level; optical beat interference; optical power distribution; relative-optical-beat-interference noise; subcarrier-multiplexed passive-optical networks; unequal mode spacing; Fiber lasers; Interference; Laser modes; Laser noise; Noise reduction; Optical fiber networks; Optical noise; Passive optical networks; Power lasers; Radio frequency;
Journal_Title :
Photonics Technology Letters, IEEE
