Title :
Fundamental limits for linearity of CATV lasers
Author :
Gorfinkel, V.B. ; Luryi, S.
Author_Institution :
Dept. of High Frequency Eng., Kassel Univ., Germany
fDate :
2/1/1995 12:00:00 AM
Abstract :
We have considered nonlinear distortions in a subcarrier multiplexed optical transmission system arising from carrier heating effects in the source laser. We included two sources of carrier heating: free-carrier absorption of the coherent radiation in the cavity, and the power flux into the active layer, associated with the input current. Resulting from the very existence of modulated optical and electrical signals, these effects cannot be avoided in any laser structure. Simple analytic expressions have been derived for the intermodulation distortion in multichannel single-mode lasers. For an 80-channel 60-540 MHz system with 3% optical modulation depth per channel, the composite second-order (CSO) distortion brought about by the hot-carrier effects is near the tolerance limit for CATV systems
Keywords :
cable television; carrier mobility; intermodulation distortion; laser cavity resonators; laser modes; nonlinear optics; optical fibre subscriber loops; optical modulation; subcarrier multiplexing; 60 to 540 MHz; CATV lasers; CATV systems; active layer; analytic expressions; carrier heating; carrier heating effects; coherent radiation; composite second-order distortion; electrical signals; free-carrier absorption; hot-carrier effects; input current; intermodulation distortion; laser structure; modulated optical signals; multichannel single-mode lasers; nonlinear distortions; optical modulation depth; power flux; source laser; subcarrier multiplexed optical transmission system; tolerance limit; Absorption; Heating; Hot carrier effects; Intermodulation distortion; Laser noise; Linearity; Nonlinear distortion; Nonlinear optics; Optical distortion; Optical modulation;
Journal_Title :
Lightwave Technology, Journal of
