A Semianalytical Method to Determine Parasitic Elements of Quantum-Well Laser

A parameter-extraction approach for the quantum- well laser, which combines the analytical approach and the empirical optimization procedure, is developed in this paper. The initial values of the parasitic pad capacitance and the feedline inductance are extracted by using a set of closed-form expressions derived from above-threshold mode input reflection coefficient on wafer measurement, and the extrinsic contact resistance and capacitance determined by using the analytical method are described as functions of the parasitic pad capacitance and the feedline inductance. Advanced Design System (Agilent commercial software) is then used to optimize only the parasitic pad capacitance and the feedline inductance with very small dispersions of initial values. An excellent fit between measured and simulated input reflection coefficients under cutoff and above-threshold biased conditions in the frequency range of 50 MHz-40 GHz is obtained.