Amplified-Spontaneous-Emission Spectrum of the Radiation Field in Surface-Emitting DFB Lasers

A.M. Shams-Zadeh-Amiri¹, W. Li², H. Wenzel³, X. Li⁴

¹ Photonami Corporation, Richmond Hill, ON L4B 1E4, Canada
² Department of Chemistry and Engineering Physics, University of Wisconsin-Platteville, Platteville, WI 53818 USA
³ Ferdinand-Braun-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, D-12489 Berlin, Germany
⁴ Department of Electrical and Computer Engineering, McMaster University, Hamilton, ON, Canada

Published in:
Journal of Lightwave Technology, vol. 24, no. 4, pp. 1824-1833, April 2006.
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Abstract:
In this paper, the authors calculate the amplified-spontaneous- emission spectrum of the radiation field in surface-emitting distributed feedback (DFB) lasers. The response of the laser cavity to the Langevin noise source in the frequency domain is obtained using the newly developed Green’s functions for the slowly varying amplitudes of the guided waves. The authors show that the power spectra from the surface and the edge are different, and this discrepancy is due to excitation of the radiation field by the interference between the counter-propagating waves inside the cavity. This feature can be properly exploited in the design of surface-emitting DFB lasers for optical communications.

Index Terms:
Amplified spontaneous emission (ASE), below-threshold spectrum, coupled-mode equations, DFB lasers, frequency-domain approach, grating-coupled surface-emitting lasers, Green’s function, Langevin force, power spectrum, second-order gratings, spontaneous emission.

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