Research On Microwave Photonics Signal Generation And Processing In Optical Fiber Communication

With the great development of the microwave photonics technology, the microwave source generation, microwave signal processing in fiber-optics and fiber-wireless convergence technology are well focused on. The representatives mentioned above are optoelectronics oscillator (OEO), microwave photonics filter and photonics frequency up-conversion.The basic principle of OEO is analyzed and a dual-loop OEO based on FBG is proposed. The obtained microwave with frequency of 4.99881998GHz is obtained with 60dB SMSR and SSB phase noise of -113dBc/Hz.The frequency doubling, quadrupling, quintupling and octupling of microwave are realized by multiplying repetition frequency of optical pulse based on fractional TALBOT effect in fiber. The theoretical computing, simulation and experiments also works out the frequency multiplication. In the experiments, the self-manufactured chromatic dispersion compensator helps in 20GHz, 40GHz, 50GHz pulse generation from 10GHz pulse with 2.8 ps width, and helps in 40GHz pulse generation from 5GHz pulse with 3 ps width.The opto-opto modulation based on carrier population dynamics in SOA is studied and the cross gain modulation and cross phase modulation are employed to up-converte 1.25Gb/s baseband signal in SOA. The involved factor such as biased current, wavelength interval and center window detuning of opical filter are considered and analyzed.A novel‘photonics frequency up-conversion with RF-local oscillator free’scheme is proposed via optical injection into a FP-LD. According to the period-one oscillation (P1) due to optical injection in FP-LD, the NRZ-OOK signal are up-converted to subcarrier modulation (SCM) signal. SCM signals with the subcarrier frequency ranging from 10GHz to 30GHz are generated and the 12GHz, 14.28GHz SCM signal are produced via 2Gb/s RZ-OOK injecting to FP-LD.According to the positive frequency chirp of SCM signal which is induced by carrier population dynamics in FP-LD, the temporal compressing of subcarrier is achieved by signal transmission in SMF. Furthermore, the second harmonic component of compressed SCM is extracted by a polarization delay interferometer (PDI). Thus the microwave SCM is doubled to millimeter wave signal. The 27.8GHz SCM signal is obtained from 13.9GHz SCM and so does the 31.4GHz millimeter wave signal from 15.7GHz SCM.The phase information of optical is converted to microwave phase information due to P1 oscillation in FP-LD in conditon of optical injection. In experiments, the 1.3Gb/s, 2.7Gb/s and 2Gb/s PSK signals are converted to 14.3 GHz, 15.12GHz and 16GHz SCM signals respectively; a series of sine phase modulated signals at 2GHz, 3GHz, 4GHz, 5GHz, 10GHz and 13GHz are converted to 22GHz, 21GHz, 24GHz, 25GHz, 10GHz and 13GHz subcarrier FM signal.