Three-section semiconductor optical amplifier for monitoring of optical gain

A 1.5- mu m multiquantum well amplifier divided into three sections with short contacts at the input and output facets is described. A simple derivation shows that the amplifier optical gain is proportional to the ratio of voltage changes at the facet contacts induced by the optical signal. Measurements of optical gain and contact voltage as a function of amplifier bias current are in good agreement with the theory.<
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