Last modified: 2018-07-25

#### Abstract

Optical properties of a semiconductor structure are the key to the understanding of semiconductor optical devices. Of great importance is the linear optical susceptibility because it represents intrinsic material or structure properties without being masked by the interaction with light. When the densities of charge carriers vary only slightly around some given values, important parameters such as the gain coefficient and the so-called Linewidth enhancement factor can be introduced to characterize the optical susceptibility [1].

The aim of this article is the study of the doping effect on the variation of the Linewidth enhancement factor of CdZnSe/ZnSSe quantum well laser. a is defined as [2]:

Where l, [4], [3] are the lasing wavelength, the differential gain, and the differential refractive index, respectively.

We assume that all radiative transitions take place between the first conduction sub-band and the first valence band. We found that the a shows the typical behaviour of the Linewidth enhancement factor, and decreases with carrier density mainly because of the decreasing differential gain.

**References**

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[1] C.H. Henry, IEEE, J. Quantum Electron, QE-18, 259 (1982).

[2] G. L. Tan, J. M. Xu: IEEE Photon. Technol. Lett: 10 (1998) 1386.

[3] T. Makino, IEEE J. Quantum Electron, QE-32, 493 (1996).

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