Title :
Dynamic and CW linewidth measurements of buried heterostructure distributed feedback lasers
Author :
Wang, S.J. ; Dutta, N.K. ; Gnauck, A.H.
Author_Institution :
AT&T Bell Lab., Murray Hill, NJ, USA
Abstract :
Measurements of frequency chirp as a function of modulation current, data rate, and bias level for the etched-mesa buried heterostructure distributed feedback (EMBH-DFB) laser are presented. The results show that the chirp increases with increasing modulation current and is significantly larger if the laser off-state is below threshold than if it is above-threshold. The 20-dB down chirp widths are in the range of 4 to 6 AA for 40 mA of modulation current at 5 Gb//s under above threshold bias. Using the EMBH-DFB laser, a system experiment over 22-km fiber at 16 Gb/s has been carried out which shows less than 0.5 dB dispersion power penalty. The continuous-wave (CW) linewidths of the asymmetric facet-coated DFB lasers are in the range of 10 to 40 MHz at 6 mW of output power. This wide range arises principally from a variation of the phase of the grating at the high-reflectivity coated facet.<>
Keywords :
distributed feedback lasers; semiconductor junction lasers; spectral line breadth; 16 Gbit/s; 22 km; 40 mA; 5 Gbit/s; 60 mW; CW linewidth measurements; asymmetric facet-coated DFB lasers; bias level; data rate; dispersion power penalty; down chirp widths; etched mesa buried heterostructure distributed feedback laser; fiber; frequency chirp; grating; high-reflectivity coated facet; modulation current; threshold bias; Chirp modulation; Current measurement; Distributed feedback devices; Etching; Fiber lasers; Frequency measurement; Gratings; Laser feedback; Power generation; Power lasers;
Journal_Title :
Photonics Technology Letters, IEEE
