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The self-consistent no parabolic calculation of a V-groove-quantum-wire (VQWR) band structure is presented. A comparison with the parabolic flat-band model of VQWR shows that both, the self-consistency and the nonparabolicity shift sub band edges, in some cases even in the opposite directions. These shifts indicate that for an accurate description of inter sub band absorption, both effects have to be taken into the account.

This article describes intersubband optical transitions in V-groove quantum wires and the resulting absorption. It is demonstrated that the optical absorption spectrum can be modified and controlled by varying the quantum wire dimensions. In addition, the importance of the conduction band nonparabolicity in calculating the absorption spectrum is pointed out. Finally, a possible application of this structure as a converter to the far-infrared wavelength range is discussed. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

An efficient semi-analytical method is developed for fast and precise assessment of the steady-state gain characteristics of the semiconductor optical amplifiers. It relies on the analytical solution for the photon densities spatial distribution, starting with the rough estimation without the nonlinear gain suppression, and subsequent refinement of the results by inclusion of the suppression. Carrier density spatial distribution is approximated either by a constant, or a piecewise constant function. Compared with the simplified wideband numerical method, which excludes the photon density spectral dependence, the semi-analytical method requires considerably lower processing resources, and, depending on the model complexity, can be between one and two orders of magnitude faster, without significant sacrifice of the accuracy. [ABSTRACT FROM PUBLISHER]

In this paper, we investigate the range of injection power and frequency detuning for which bistability of the injection-locked semiconductor Fabry–Perot laser diode can be achieved and preserved. The analysis is based on a detailed model of the multimode rate equations and material gain. The stationary analysis shows that there is a region of the injection power and detuning for which the laser has three stationary states. However, the stability analysis shows that for a wide range of injection powers and detuning, the two of three stationary states are stable and provide bistability. One of these states is the result of injection locking, whereas the other is mainly a consequence of the interplay between injection-locked and unlocked modes. The difference of the side-mode-suppression ratio between the stable states is of the order of 20 dB and it can increase with detuning and decrease with mode order. [ABSTRACT FROM PUBLISHER]

This paper presents material-gain and threshold-current calculation of a InGaAs-InP quantum-wire laser in the framework of the k · p method, with included conduction-band nonparabolicity for the first time. The method for band-structure calculation is based on conformal mapping and Fourier expansion. The calculation shows that high material gain (7000 cm[sup -1]) can be achieved at room temperature for polarization along the free axis of the quantum wire. We propose an optimized laser structure, based on a stack of quantum wires. [ABSTRACT FROM AUTHOR]