Fixed low-frequency pilot analysis for self-calibrated frequency response characterization of electro-absorption modulated lasers

An approach to measuring high-frequency responses of electro-absorption modulated lasers (EMLs) is proposed based on fixed low-frequency pilot analysis. The fixed low-frequency pilot is inserted into the microwave driving signal loaded on the EML through amplitude modulation. Then, the high-frequency response of EML can be obtained by extracting and analyzing the pilot (kHz level) after photodetection, thereby realizing the low-frequency detection for EML measurement. Moreover, the method is independent of the responsivity fluctuation of the photodetector due to the fixed frequency analysis and enables the self-calibrated frequency response measurement of high-speed EML.