Title :
Transition From Perturbed to Coupled-Cavity Behavior With Asymmetric Spectral Emission in Ridge Lasers Emitting at 1.55 μm
Author :
Roycroft, B. ; Lambkin, P. ; Riesner, S. ; Corbett, B. ; Donegan, J.F.
Author_Institution :
Tyndall Nat. Inst., Cork
Abstract :
We have investigated a series of ridge waveguide lasers with deeply etched slots in the ridges. The slots do not penetrate the active region, but are deep enough to strongly perturb the longitudinal modes. By the addition of slots, a transition between perturbed-mode and coupled-cavity behavior is crossed. With a group of four or more slots, the below-threshold amplified spontaneous emission spectrum from each end of the laser has different periods and the facet-facet oscillations are suppressed indicating that the different sections have become quasi-independent. A model using a distributed emitter in the cavity reproduces this behavior. Above threshold, the single contact coupled cavity lasers are single mode with greater than 30-dB sidemode suppression ratio over a wide range of currents
Keywords :
coupled mode analysis; etching; laser cavity resonators; laser modes; semiconductor lasers; superradiance; waveguide lasers; 1.55 mum; amplified spontaneous emission; asymmetric spectral emission; coupled cavity lasers; coupled-cavity behavior; deep etching; distributed emitter; facet-facet oscillations; longitudinal modes; perturbed mode; ridge lasers; semiconductor laser; side mode suppression ratio; single mode lasers; waveguide lasers; Distributed feedback devices; Etching; Laser feedback; Laser modes; Laser transitions; Laser tuning; Optical coupling; Semiconductor lasers; Spontaneous emission; Waveguide lasers; Coupled mode analysis; laser modes; semiconductor lasers; wavelength-division multiplexing;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2006.889106