Authors: B Cakmak T Karacali S Yu
Publish Date: 2005/06/14
Volume: 81, Issue: 1, Pages: 33-37
Abstract
This paper reports a theoretical design of chirped mirrors in 13μm doublesection semiconductor lasers to achieve high reflectivity and dispersion compensation over a broad bandwidth Analytic expressions for reflectivity group delay and group delay dispersion are derived We use for the first time chirped air/semiconductor layer pairs as mirrors for higherorder dispersion compensation in semiconductor lasers Our optimised calculations demonstrate that the broadband mirrors designed consist of a total of only 12 air/semiconductor layers and achieve a reflectivity higher than 998 a smooth group delay and almost stable dispersion in the laser cavity over a 100nm bandwidth Due to a high index contrast of both types of the layers nl = 1 nh~ 35 a highreflectivity bandwidth of 700 nm is obtained in 13μm semiconductor lasers We also compare our results with that of a commercial simulation program and show a good agreement between them As a conclusion we assume from the theoretical results that air/semiconductor layer pairs with varying thicknesses used at one end of doublesection semiconductor lasers can lead to femtosecond optical pulse generation using modelocking techniques
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