analytical investigation of frequency behavior in tunnel injection quantum dot vcsel

The frequency behavior of the tunnel injection quantum dot vertical cavity surface emitting laser (tiqd-vcsel) is investigated by using an analyticalnumerical method on the modulation transfer function. the function is based on the rate equations and is decomposed into components related to different energy levels inside the quantum dot and injection well. in this way, the effect of the tunneling process on the improvement of the laser frequency response is determined. generally, the components of the modulation transfer function in the wetting layer and the excited state limit the total laser bandwidth. of course, the component associated with the tunneling process increases overall system bandwidth. it is shown that for currents above threshold, the carrier density at the excited state in tiqd has a slight slope, unlike the conventional quantum dot (cqd). it will improve the frequency response of the tunnel injection structure. it can be attributed to the difference in pauli blocking factor values at the excited state and the ground state in the two structures.