Refractive index, capture rate and sensitivity of quantum dot lasers to optical feedback

The line-width enhancement factor and the relative intensity noise spectrum of quantum dot semiconductor lasers were measured. The sensitivity to optical feedback of quantum dot semiconductor lasers was compared to quantum well semiconductor lasers. A reduced sensitivity of 20 dB compared to quantum well semiconductor lasers was observed. Rate equations describing the capture of carriers from the quantum well into the dots was used as basis in providing an explanation for the reduced sensitivity to optical feedback.