Facet reflectivity and low-frequency noise in the light output of LED and superradiant diodes

The influence of the reflection coefficient of cleaved facets from a double heterostructure laser on the l/f noise in light output is investigated. The experimental noise results are obtained by partially embedding the laser in Canada balsam, resulting in a decrease of the reflection coefficient, and by evaporating an aluminum coating, which results in a fully reflecting facet. These experimental results are shown to be in full agreement with an extension of existing models proposed by Fronen and Vandamme (l988). The 1/f noise arising from fluctuations in the refractive index is calculated, and it is concluded that this noise is negligible compared to the bulk noise in semiconductor lasers.<
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