Single-carrier single-drive two-tone optical stimulus generated by self-heterodyne interferometry for analyzing third-order intermodulation distortion (IMD3) of photodiodes.

A single-carrier single-drive two-tone method is proposed for analyzing the third-order intermodulation distortion (IMD3) of photodiodes (PDs) based on electro-optical self-heterodyne interferometry. A phase-modulated optical carrier is combined with its frequency-shifted replica as the practical optical stimulus for PD. Our method allows for a modulator-spurious-free analysis of PD by fully de-embedding the contribution of the wanted two-tone stimulus from that of the spurious harmonics in the overall stimulus, with the help of the Jacobi-Anger identity. This is the most efficient solution with minimal setup for extracting the IMD3 of PDs, as it is believed to be the first demonstration of bias-free, frequency-swept, and modulator-spurious-free analysis for high-power PDs using only a single-carrier single-drive optical stimulus.