Title :
Chirp reduction using push-pull modulation of three-contact lasers
Author :
Nowell, M.C. ; Zhang, L.M. ; Carroll, J.E. ; Fice, M.J.
Author_Institution :
Dept. of Eng., Cambridge Univ., UK
Abstract :
Low-chirp modulation of three-contact distributed-feedback (DFB) lasers is experimentally demonstrated, using a push-pull modulation scheme. When the laser was modulated with a 2.0-Gb/s pseudorandom bit sequence, the -20-dB linewidth was measured to be 0.055 nm after deconvolving the measurement equipment´s response. The results are simulated using a large-signal time-domain model that illustrates the mechanisms responsible for the low chirp. The grating structure is shown to have a significant effect on the performance of the device under push-pull modulation.<>
Keywords :
diffraction gratings; distributed feedback lasers; optical modulation; refractive index; semiconductor lasers; 2.0 Gbit/s; DFB lasers; chirp reduction; distributed-feedback lasers; equipment response deconvolution; grating structure; large-signal time-domain model; linewidth; low chirp; low-chirp modulation; pseudorandom bit sequence; push-pull modulation; push-pull modulation scheme; three-contact lasers; Charge carrier density; Chirp modulation; Distributed feedback devices; Electrons; Frequency; Gratings; Laser feedback; Laser modes; Optical modulation; Refractive index;
Journal_Title :
Photonics Technology Letters, IEEE
