1- Amirkabir university of technology
Az.zahra university,tehran
2- Tarbiat Modarres University
3- Amirkabir university of technology
Abstract: (4433 Views)
In this paper, the effects of reflected waves of the facets on the internal optical intensity of semiconductor DFB lasers are investigated. The uniformity of optical intensity along the cavity length is evaluated with flatness parameter. The dependence of this parameter on coupling coefficient, reflectivity and grating phase at the facets is also studied. This investigation shows that in some structures reflected waves of the facets cause optical intensity along the cavity length to have more uniformed distribution than a DFB laser with anti-reflective facets. It is also shown that flatness parameter is very sensitive to grating phase .Thus it is necessary for designing a DFB laser to consider the effects of reflected wave and grating phase at both ends of cavity in order to increase the stability of the laser against SHB (Spatial Hole Burning) effect. The effects of reflectivity and grating phase on longitudinal distribution of photon and carrier density above threshold are investigated, too.
Received: 2010/10/3 | Accepted: 2010/10/3 | Published: 2010/10/3