Research On Key Technologies For The Measurement Of High-Speed Optoelectronic Chips

Optoelectronic devices,as the basis of realizing high-speed communications,lowlatency data exchange and real-time signal processing,are developing in the direction of miniaturization and integration to meet the growing demand for the system performance.At present,the optoelectronic chip design technology develops rapidly,but the test technology shows a serious mismatch,as many optoelectronic chips have a design bandwidth of hundreds of gigahertz,but few measurement solutions can achieve this bandwidth.The measurement technology of high-speed optoelectronic chips still needs to be developed and improved.This dissertation focuses on improving the measurement bandwidth,achieving a highly detailed measurement,and simplifying the test process of high-speed optoelectronic chips.The following research work has been carried out,and some problems with optoelectronic chip tests have been substantially solved.1.The time-domain and frequency-domain characteristics of ultrashort pulse light emitted by mode-locked laser is studied.The influence of the pulse shape,width,peak power,and chirp parameters of the ultrashort pulse on the photonic sampling results of optoelectronic devices is evaluated,and the electrical spectral response characteristics of the ultrashort pulse are summarized.Based on these research results,a mode-locked fiber laser that can be used for the measurement of high-speed optoelectronic integrated chips is designed and implemented.2.Two novel methods based on half-frequency sampling and two-tone sampling are proposed for the measurement of photodetector(PD)chips.In the half-frequency sampling scheme,the frequency of the sweeping microwave signal is configured to be half of the comb frequency in the beat signal of the ultrashort pulse light,and the sampling realizes the self-reference elimination of the uneven electrical spectral response of the ultrashort pulse light and the response of the optic-electro auxiliary device at the same time.With the help of microwave de-embedding technology,the high-frequency intrinsic response of the PD chip is finally obtained.In the two-tone sampling scheme,two microwave sources are configured to synchronously output frequency-wept signals with a fixed frequency difference to achieve the measurement of the PD chip at any operation frequency,which not only has the ability of self-calibration measurement,but also can realize the high-precision characterization of PD chip.Both methods have the capability to implement the characterization of PD chips without a good impedance match.3.A single-tone sampling method and a two-tone sampling method are proposed for the microwave characterization of electro-optic modulator(EOM)chips.In the singletone sampling scheme,a frequency-wept microwave signal is used to drive the EOM chip under test,and the response information of the EOM chip is down-converted and mapped to a fixed low-frequency signal,which realizes the self-reference elimination of the response of the auxiliary device.To further get rid of the operation bandwidth limits of the auxiliary device,the time-domain information of the pulse light is obtained,which is used to recover the ultra-wideband electrical spectral response of the pulse light.Finally,with the help of microwave de-embedding technology,the intrinsic responses of the EOM chip are obtained.In the two-tone sampling method,the high-frequency response information of the EOM is also mapped to two fixed low-frequency signals,which does not require separate measurement of the electrical spectral response.Both the proposed schemes can achieve the intrinsic response extraction of EOM chips only by using a lowspeed PD.4.A novel photonic sampling method is proposed for the measurement of microwave photonic link(MWPL)chips.In the scheme,up-conversion sampling,downconversion sampling,and sweep-frequency measurement are implemented to decouple the intrinsic responses of the EOM and the PD cascaded on the MWPL chip,which overcomes the problem with MWPL chip tests.The proposed scheme can achieve the simultaneous measurement of the EOM and the PD in any integrated system without destroying the chip structure or using additional standard optoelectronic auxiliary devices,which is efficient and universally applicable.