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 s...

We present a numerical study of the effects of carrier diffusion and spatial hole-burning in vertical-cavity surfaceemitting lasers under gain switching. Our model includes spatial and temporal dependences of both the optical field and the carrier density. Results show that spatial hole burning places a limit on the minimum achievable pulse width. We demonstrate that spatial hole-burning can be...

The impact of upper state lifetime and spatial hole burning on pulse shape and stability in actively mode locked QCLs is investigated by numerical simulations. It is shown that an extended upper state lifetime is necessary to achieve stable isolated pulse formation per roundtrip. Spatial hole burning helps to reduce the pulse duration by supporting broadband multimode lasing, but introduces pul...

We demonstrate a passively mode-locked thin-disk Yb:YAG laser that generates solitonlike pulses with durations that are continuously tunable in a very wide range from 3.3 to 89 ps or from 0.83 to 1.57 ps. The average powers are typically ~12 W . Previously [Opt. Lett. 25, 859 (2000)], only pulse durations in a narrow range near 0.7 ps could be obtained from such lasers because of the effect of ...

Single-longitudinal-mode operation in a homogeneously broadened solid-state laser is often impeded by spatial hole burning. To maintain a single longitudinal mode, it is necessary to eliminate spatial hole burning, for example, by introducing quarter-wave plates at both ends of the gain medium' or by using a ring cavity.2 In a standingwave resonator, an additional wavelength-selective element, ...

The correlation between the amplitude fluctuations of two laser beams emitted by a semiconductor laser is calculated using a semiclassical laser model including vacuum fluctuations present at the laser facets as well as phenomena such as spatial hole burning and gain suppression. A thorough analysis shows strong influence of the laser structure and parameters. We concentrate on the case of Fabr...

We derive and test a generalization of the steady-state ab initio laser theory (SALT) to treat complex gain media. The generalized theory (C-SALT) is able to treat atomic and molecular gain media with diffusion and multiple lasing transitions, and semiconductor gain media in the free carrier approximation including fully the effect of Pauli blocking. The key assumption of the theory is stationa...

A quasi-3 D simulation for quantum well (QW) distributed feedback (DFB) laser diodes is presented. Longitudinal effects such as the nonuniformity of the optical intensity, local gain and spontaneous emission are considered as well as lateral effects such as current spreading and quantum carrier capture. The simulation is performed by solving several 2-D cross-sections using Minilase II and a 1-...