Abstract: Two methods for analyzing the high frequency effect of the packaging techniques for photodiodes are presented.The first method compares the frequency responses of the photodiode before and after packaging,and the second one is based on the relations between the scattering parameters of the packaging network,photodiode chip,and module.In the experiment of the TO photodiode module,results from the two methods show coherence,which indicates that the methods established are effective for practical applications.Analysis results also denote that there is a resonance between the inductance in the bonding wire and the parasitic capacitance in both the feedthru of the TO header and the photodiode chip.This resonance can be used to compensate for the overall frequency response of the device.By adjusting the values of the inductance and capacitance,an optimized frequency response of the TO photodiode module is achieved.

Key words: optical communication, photodiode, TO packaging, scattering parameters, parasitics