DFB Laser Arrays with Precise Channel Separation and High Coupling Coefficient

Tang, S., Hou, L. , Chen, X. and Marsh, J. H. (2017) DFB Laser Arrays with Precise Channel Separation and High Coupling Coefficient. In: Conference on Lasers and Electro-Optics/Europe and the European Quantum Electronics Conference, Munich, Germany, 25-29 June 2017, ISBN 9781509067367 (doi:10.1109/CLEOE-EQEC.2017.8086369)

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Abstract

Summary form only given. Distributed feedback (DFB) semiconductor laser arrays operating at precisely controlled wavelengths are important components for wavelength division multiplexing networks. Recently, precise wavelength control has been realized by the reconstruction-equivalent-chirp (REC) technique based on sampled Bragg gratings (SBGs) [1]. However, the effective coupling coefficient, κ, of a sampled grating is necessarily reduced substantially from that of a uniform grating, compromising the single longitudinal mode (SLM) performance of DFB lasers. To overcome this, designs of SBGs with phase shifted grating sections have been proposed and demonstrated in fibre lasers. In these structures, the (not required) zeroth-order mode is suppressed while the index modulation experienced by the nonzeroth-order channels is enhanced, the ±1st order channels being of particular interest [2]. Here, for the first time, we apply a combination of π-phase shifted gratings with the REC technique to DFB diode lasers. Using a single electron beam lithography (EBL) step we have demonstrated an increased effective coupling coefficient κ and have fabricated an eight-channel laser array with a spacing of 100 GHz (~0.8 nm @1550 nm). For the same channel spacing using conventional 0th order gratings (Fig. 1(a)), a resolution of about 0.125 nm would be required, which is beyond the typical resolution limit of 0.5 nm of EBL machines.

Item Type:Conference Proceedings
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Marsh, Professor John and Tang, Mr Song and Hou, Dr Lianping
Authors: Tang, S., Hou, L., Chen, X., and Marsh, J. H.
College/School:College of Science and Engineering > School of Engineering
College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
ISBN:9781509067367
Copyright Holders:Copyright © 2017 IEEE
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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