Linewidth broadening of SCH quantum-well lasers enhanced by carrier fluctuation in optical guiding layers

A theoretical analysis of the spectral linewidth in separate-confinement heterostructure (SCH) quantum-well (QW) semiconductor lasers is given by taking into account the dynamics of the injected carriers in the optical guiding and barrier layers. The analytical result indicates that the linewidth tends to be abruptly broadened due to the dynamics of the carriers overflowing into the optical guiding layers, typically in a single-quantum-well structure. In addition, a superior effect on the linewidth reduction is predicted by adoption of a potential controlled (or modulation-doped) structure.<
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