Dependence of coupling coefficient and lasing wavelength on injection current in pure gain-coupled distributed feedback semiconductor lasers

作者：Aliannezhadi Maryam; Shahshahani Fatemeh^*; Ahmadi Vahid

来源：Journal of Modern Optics, 2010, 57(10): 859-865.

DOI：10.1080/09500340.2010.493242

• DFB laser
• pure gain-coupled
• semiconductor laser

A theoretical analysis of purely gain-coupled distributed feedback lasers (PGC-DFB) with antireflection facets is given. The effects of longitudinal non-uniformity of photon and carrier density above a threshold circumstance are considered. In addition, the influence of carrier-induced refractive index change on the coupling coefficient of the PGC-DFB structure is assumed. It is shown that the coupling coefficient in this structure varies with injected current and it gets a real part or an index coupled term. As a result the normalized coupling coefficient, kappa L, becomes a complex number. So, above the threshold condition, the PGC-DFB laser operates like a complex coupled one. Variation of the oscillation wavelength and the threshold gain of the PGC-DFB laser in terms of current is analyzed too. Numerical analysis shows that this structure has wavelength tunability with respect to current. The theoretical model is based on the self-consistent solution of coupled wave equations and the carrier rate equation by the transfer matrix method.

• 出版日期2010