Coherent lightwave transmission using heterodyne detection has been widely recognized as an attractive optical fiber communication system for the next generation. The fine channel selectivity provided by the heterodyne detection is well suited for a broadband optical frequency-division-multiplexed (FDM) system which has great potential for applications in the subscriber loop. One key component in such an optical FDM system is a frequency tunable laser source. Several approaches for an electronically tunable laser structure have been proposed recently.1-5 A continuous tuning range as large as 58 Å has been reported.5 Among the various device structures reported so far, the double-sectioned DFB laser is the simplest structure to fabricate and has exhibited a useful frequency tuning range between 10 and 20 Å (130-260 GHz). We describe here a new characterization technique for the double-sectioned DFB laser and report the detailed operating characteristics of such a device.
© 1988 Optical Society of AmericaPDF Article