Electrical spectra characterization of mode-locked fiber laser and application for high-speed optoelectronic devices measurement

A calibration-free and three-in-one electro-optic frequency sweeping-based method is proposed for the electrical spectra and frequency response characterization of mode-locked fiber laser (MLFL) MLFL, intensity modulators (IMs), and photodetectors (PDs) with a shared measurement scheme. By carefully setting the frequency relationship between the swept frequency, the extra influence from other assisted devices besides device under test (DUT) is fully cancelled out by analyzing the power ratio between the single-tone driving signal and electrical signals of the MLFL after photodetection. Moreover, the wideband requirement of the assistant devices is reduced by half to that of the DUT in the cases of the MLFL, IM, and PD measurement, respectively. The microwave characterization of the MLFL, IM and PD are experimentally extracted with the proposed method and the measured results are compared to those obtained with the traditional electro-optic frequency sweeping method to check the consistency and accuracy.