Research On Multi-waveform Generation And Angular Velocity Measurement Technology Based On Photoelectric Oscillator

Microwave photonics technology is an emerging technology that combines the advantages of microwave technology and photonics.It aims to solve the bandwidth and speed problems which is beyond the ability of traditional microwave technology by utilizing the inherent advantages of optical technology such as high speed,large bandwidth,low loss and anti-electromagnetic interference.Among them,photo-generated microwave technology,photoelectric microwave oscillator(OEO)for example,breaks through the limit of phase noise of traditional microwave sources and has become a hotspot research in international range.In order to make more progress,this thesis focuses on the OEO-based microwave waveform generation technology and angular velocity measurement technology.The thesis explores a new generation method of microwave waveform signals,aiming at reducing the complexity and cost of the system and improving system flexibility and signal quality.Besides,because Microwave frequency measurement is more accurate than power measurement,precision angular velocity measurement is achieved under the premise of sensitivity assurance by utilizing microwave photon technology to convert optical angular velocity measurement system into microwave photon angular velocity measurement system through Sagnac effect.The main work of this thesis can be abstracted as follow:The generation of multi-waveform:1.A new photonic approach for triangular waveform generation by making full use of the polarization sensitive characteristic of the single-drive Mach-Zehnder modulator(MZM)is proposed and experimentally demonstrated.Triangular waveforms with repetition frequencies of 8 GHz,10 GHz and 12 GHz are successfully generated,respectively.2.The 9 GHz,10 GHz,12 GHz triangular waveform is composited in time-domain by using characteristics of selecting frequency in the phase of injection locking.3.Using the modulation characteristics of cascade modulation and time-domain optical pulse shaping method,a variety of waveform signals with a frequency of 3 GHz is generated,including a square waveform,a triangular waveform,a sawtooth waveform wave(or reversed-sawtooth)and amultiplied sawtooth waveforms(or reversed-sawtooth);4.Based on the proposed time domain pulse shaping theory as well as wavelength dual loop OEO system,full-duty-cycle and high quality square,sawtooth(reversed-sawtooth)and triangular waveform signals with low phase noise at 4.9641 GHz are achieved.5.10 GHz sawtooth(or anti-aliased)waveform,triangular waveform and Gaussian pulse signal are generated with low phase noise and low time jitter by combining dual loop OEO and frequency domain to time domain mapping techniques.Angular velocity measurement:a new scheme of angular velocity measurement method based coupled optoelectronic oscillator(COEO)is proposed.In COED resonant cavity,optical carrier and one of the first-order sidebands are separated by polarization delay interferometers,and propagate in opposite directions in the Sagnac loop.The rotation-induced phase difference between optical carrier and first-order sideband produces a frequency shift in COEO system.Moreover,for bidirectional system,the trends of resonant frequencies shift are opposite.Therefore,the difference of bidirectional resonant frequencies is the summation of unidirectional rotation-induced frequency shift.And less-complex,high-resolution microwave detection technology is used to improve the detection resolution of frequency difference.Therefore,a high-sensitivity angular velocity measurement system is implemented,with a sensitivity scale of 172.04 kHz/(rad/s).Theoretically,a minimally detectable angular velocity is 1.2°/h.