Xuedi Xiao

Tunable dual frequency optoelectronic oscillator with low intermodulation based on dual-parallel Mach-Zehnder modulator

A tunable dual-frequency optoelectronic oscillator (OEO) based on dual-parallel Mach-Zehnder modulator (DPMZM) with low intermodulation is proposed and experimentally demonstrated. Two tunable electronic band-pass filters are used to select the oscillation modes of the two oscillating frequencies to achieve tunable dual-frequency OEO (TDF-OEO). Each of the two selected modes are modulated onto one sub-modulator of the DPMZM. By choosing proper bias conditions of the DPMZM, the intermodulation components generated by the dual-frequencies are suppressed. The tuning range of the TDF-OEO is from 1 GHz to 15 GHz in the experiment. We also discussed and experimentally demonstrated the tuning limitation of this dual frequency system.

Tunable ultraflat optical frequency comb generator based on optoelectronic oscillator using dual-parallel Mach–Zehnder modulator

Abstract. A tunable ultraflat optical frequency comb generator based on the optoelectronic oscillator (OEO) using a dual-parallel Mach–Zehnder modulator (DPMZM) is proposed and experimentally demonstrated. By incorporating a tunable DPMZM-OEO, five comb lines were generated with frequency spacing from 5 to 12 GHz under a wide central wavelength tuning from 1530 to 1560 nm, and a comb flatness of 0.3 dB is obtained. The corresponding signal generated by the DPMZM-OEO is also measured, and the phase noise of the frequency tunable signals is as low as −125  dBc/Hz at 10-kHz frequency offset.

Photonic generation of multi-frequency phase-coded microwave signal based on a dual-output Mach-Zehnder modulator and balanced detection

A photonic scheme to generate a multi-frequency phase-coded microwave signal based on a dual-output Mach-Zehnder modulator (DOMZM) and balanced detection is proposed in this paper. The DOMZM driven by an electrical coding data modulates a coherent multi-wavelength light source (CMWL), and a balanced photodetector (BPD) demodulates the output of the DOMZM; as a result, a multi-frequency phase-coded microwave signal is generated. Experiments generate two two-frequency phase-coded signals: one is 5GHz/10GHz signal with a coding rate of 2Gb/s, and the other is 10GHz/20GHz signal with a coding rate of 4Gb/s. Their autocorrelation results show a good pulse compression capability. Each frequency of a two-frequency signal has similar performances with the other in terms of peak-to-side lobe ratio (PSR) and the full width at half-maximum (FWHM) of the main lobe. The proposed scheme can be applied to radar to reduce false detections in adverse conditions. With its potential flexible frequency agility, it can be used for jamming resistance and elimination of the Doppler blind speed during moving target detection.