An Analytical Method to Determine Small-Signal Model Parameters for Vertical-Cavity Surface Emitting Lasers

A parameter-extraction approach for small-signal model of the vertical-cavity surface emitting lasers (VCSELs), which combines the analytical approach and empirical optimization procedure, is developed in this paper. The cutoff operation of the VCSELs is utilized to extract the values of the pad capacitances, feedline inductance by using a set of closed form expressions derived from cutoff mode input reflection coefficient on wafer measurement. A semianalytical method has been used to determine the extrinsic resistance, and intrinsic oxide aperture junction resistance and capacitance under above-threshold bias condition. An excellent fit between measured and simulated input reflection coefficients under cutoff and above-threshold biased condition in the frequency range of 50 MHz-20 GHz is obtained for VCSELs with different oxide-confined aperture size over a wide range of bias points.