Carrier transport limited bandwidth of 1.55 μm quantum‐well lasers

We present the first measurements of the dynamic response of InGaAs/InGaAsP multiquantum‐well lasers which clearly show the effect of the carrier transport phenomena on the modulation response. Using our parasitic‐free optical modulation method, we separate an intrinsic RC‐like component in the frequency response from normal resonance behavior. The bandwidth is strongly limited by this low‐pass rolloff that can be described by a structure‐dependent transport time. It is shown that, therefore, the K factor may not be a reasonable quantity for evaluating the ultimate bandwidth.