By Topic

Multiple-Mode Behavior of Circular-Grating-Coupled Distributed Feedback Lasers

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
Li, X.F. ; Sch. of Electr. & Electron. Eng., Nanyang Technol. Univ., Singapore ; Yu, S.F.

Multimode characteristics of circular-grating-coupled distributed feedback (CGC DFB) lasers are studied theoretically. A modified time-domain finite-difference method is used to solve the time-dependent coupled-mode equations and carrier rate-equation in a self-consistent manner. It is found that, at a moderate injection current density (les 4 times its threshold), the high-order radial modes with fundamental azimuthal profile can be excited when either (1) the grating duty cycle is in the range between 0.35 and 0.5, (2) the phase shift of the grating center is greater than pi, or (3) the facet reflectivity is greater than 0.2. On the other hand, switching between the modes with fundamental and first-order azimuthal profiles is observed when the grating duty cycle is either ~ 0.08 or ~ 0.45 . Switching of azimuthal modes is also observed if facet reflectivity is greater than 0.02. Outside these conditions or the lasers with duty cycle greater than 0.5, stable single-mode operation is observed. Therefore, the design of single-radial and azimuthal mode CGC DFB lasers can be realized.

Published in:

Lightwave Technology, Journal of  (Volume:26 ,  Issue: 19 )