Research On Frequency-Domain Characterization Of High-Speed Optoelectronic Devices Based On Self-Heterodyne

High-speed optoelectronic devices are essential components as optical modulation and photodetection,and their frequency-domain characteristics are key parameters for evaluating operating bandwidth and speed.Therefore,high-resolution and multi-dimension(amplitude/phase)frequency-domain characterization of high-speed optoelectronic devices is critical to construct optical communication system with high spectral efficiency and microwave photonics system with high-performance.The optical spectrum analysis method is simple for characterizing electro-optical intensity/phase modulators,while it is limited by measurement resolution(about GHz)and cannot work for photodetectors(PDs).The electrical spectrum analysis method can provide the ultra-high resolution measurement of electro-optical intensity modulators and PDs,while it is unable to characterize electro-optical phase modulators(EOPMs)and requires extra de-embedding the contribution of electro-optic and photoelectric devices.The optical heterodyne analysis method can be applicable for characterizing electro-optical modulators and PDs,while the measurement resolution and accuracy suffer from wavelength drifting and linewidth of optical source.In this thesis,we have studied frequency-domain characterization of high-speed optoelectronic devices based on self-heterodyne technology for addressing the low resolution of the optical spectrum analysis method,the extra cascading calibration of the electrical spectrum analysis method and the dependence on the heterodyne source with ultra-narrow linewidth and frequency stabilization of the optical heterodyne analysis method.Moreover,frequency-domain characterization of high-speed Mach-Zehnder modulator(MZM),high-speed EOPM and high-speed PD is researched by systematacially theoretical and experimental demonstrations.Besides,a self-calibrated frequency-domain measurement system is presented for characterizing high-speed optoelectronic devices based on self-heterodyne technology.The main research contents of this thesis are as follows:(1)We got the following innovations in the research of frequency-domain characterization of high-speed MZM.A self-calibrated measurement method of chirp parameter of high-speed MZM is proposed based on acousto-optic frequency-shifted heterodyne,which achieves a self-calibrated measurement of chirp parameter of high-speed MZM with any extinction ratio(ER)by eliminating the impacts from ER of the MZM and uneven responsivity of the PD.A self-calibrated measurement method of half-wave voltage and chirp parameter of high-speed MZM is proposed based on relay frequency-shifted heterodyne,which enables simultaneous measurement of half-wave voltage and chirp parameter of high-speed MZM without considering ER of the MZM and uneven responsivity of the PD by mapping the optical spectrum in optical domain to the heterodyne spectrum in electrical domain.A self-calibrated measurement method of half-wave voltage of high-speed MZM is proposed based on two-tone modulation heterodyne,which allows to extracting high-frequency half-wave voltage of push-pull MZM,dual-electrode MZM and dual-parallel MZM from the sub-MHz electrical spectrum analysis.The two-tone modulation heterodyne method not only avoids any correction for the roll-off responsivity of photodetection,but also largely saves the bandwidth requirements of the PD and electrical spectrum analyzer(ESA).(2)We got the following innovations in the research of frequency-domain characterization of high-speed MZM.A self-calibrated measurement method of half-wave voltage of high-speed EOPM is proposed based on acousto-optic frequency-shifted heterodyne,which is demonstrated by three frequency-shifted heterodyne schemes based on close-frequency detection,half-frequency detection and low-frequency detection through removing the extra calibration for the uneven responsivity of the PD.More importantly,the frequency-shifted heterodyne scheme based on low-frequency detection achieves high-frequency half-wave voltage of the EOPM measurement with MHz electrical spectrum analysis so that it largely saves the bandwidth requirements of the PD and the ESA.A self-calibrated measurement method of half-wave voltage of the EOPM is proposed based on relay frequency-shifted heterodyne,which realizes a self-calibrated measurement and heterodyne spectrum mapping for half-wave voltage of high-speed EOPM in the case of avoiding the extra calibration for the uneven responsivity of the PD.(3)We got the following innovations in the research of responsivity characterization of high-speed PD.A self-calibrated measurement method of high-speed PD responsivity is proposed based on acousto-optic frequency-shifted heterodyne,which avoids the extra calibration for frequency response of electro-optic devices.A self-calibrated measurement method of high-speed PD responsivity is proposed based on two-tone modulation heterodyne,which not only eliminates the extra calibration for the uneven response of electro-optic devices,but also extends twice the measuring range and simplifies the measurement system compared with traditional methods.(4)A self-calibrated and integrated high-frequency measurement platform is constructed based on relay frequency-shifted heterodyne,which can simultaneously measure half-wave voltage and chirp parameter of high-speed MZM,half-wave voltage of high-speed EOPM and responsivity of high-speed PD with simple frequency configuration.The measurement platform not only avoids impacts from other assistant optoelectronic devices,but also enables a high-resolution and self-calibrated measurement of muti-device and muti-parameter.(5)The self-heterodyne technology is also expanded for microwave frequency measurement(MFM)and a photonic-assisted MFM system is proposed based on frequency-configurable pilot tones.The MFM system enables flexible frequency range and high-resolution measurement by configuring two pilot frequencies.Moreover,it eliminates the poor stability and tunability of the adjustable elements in the frequency-amplitude mapping method and avoids dual-channel high-speed photodetection and broadband microwave power measurement in the electrical power mapping method.