Broadband Microwave Photonic Signal Manipulation And Processing

Optical transmission has been regarded the key technique of high-speed and large capacity communication,owing to its inherent advantages of broad bandwidth and low loss.On the other hand,microwave communication also plays an important role in wireless communication network owing to its mobility and reconfiguration.The advantage and disadvantage of the photonic and microwave technologies facilitate the intersection of these two fields.Therefore,microwave photonic has been emerging as a novel interdisciplinary,which is aimed at breaking the bottleneck of traditional microwave technology on bandwidth or transmission rate via the technique of optics.Microwave photonic includes many fields,such as microwave signal generation,transmission and processing etc.It has been ultilized in many civil and military applications,including wireless communication,cable television,remote sensor,radar and electronic warfare.More new techniques and approaches of signal processing have been incorported into the system of microwave photonic,which required the larger tunability of system.In order to offer the potential technique for an intelligent and reconfigurable next-generation optical access networks,this work focuses on the reasearch of broadband microwave photonic signal manipulation and processing.In this dissertation,we firstly analyze the fundamental concepts,limitations,milestion in microwave photonic signal processing,and then the technique of microwave photonic signal generation,microwave photonic filter,microwave frequencies fast switching and microwave frequency measurement are extensively studied as the following parts:For all-optical filter,by creating the model of cascaded-,parallel-Mach-Zehnder Interferometry(MZI)structure and analyzing related parameters,we successfully achieve all-optical comb filter with tunable bandwidth,central frequency and free spacing ratio(FSR)based on cascaded MZI;and then a polarization diversified comb filter is demonstrated,which the parameters of its transfer function on orthogonal polarization states can be independently tuned,such as free spectral range(FSR),central frequency.They can offer the manipulation of optical spectrum in microwave photonic signal processing,such as the optical spectrum shaper in microwave photonic signal generation.Using low-loss cascaded silicon-nitride ring resonators,we demonstrate a disruptive approach of phase-manipulated phase modulation to intensity modulation(PM-IM)conversion to achieve a programmable photonic RF filter with variable shape,bandwidth and central frequency.For microwave photonic signal generation,microwave photonic signal generation based on the heterodyne detection and the frequency to time mapping(FTTM)is demonstrated respectively.First,the 2PSK signal with tunable carrier frequency is generated based on the heterodyne detection in a simple structure of two-passes-on-one-arm.And the UWB signals with a tunable 1-,2-,3-order and positive or negative polarity is generated based on FTTM and a reconfigurable optical spectrum shaper.By introducing the crosstalk in the process of FTTM,an arbitrary waveform generator is successfully achieved based on the crossed FTTM.For fast microwave frequencies switching,two kinds of fast microwave photonic filters are proposed,which can be applied for fast microwave frequencies switching.The modulation format of optical modulator can be dynanmically controlled based on the hybird modulation of a RF signal and data on an optical modulator.And then the central frequency of a microwave photonic comb filter can be rapidly switched with a frequency spacing of FSR/2 at a speed of <100ps.By further harnessing the stimulated Brillouin scattering effects(SBS)and the principle of cancellation filter,the transfer function of filter can be switched between the single passband and the single stopband with a very narrow bandwidth of ~MHz at a speed of <100ps.For microwave frequency measurement,on-chip wide-rang,high precision multiple microwave frequencies measurement is studied.We propose an approach of multiple microwave frequencies measurement using chip-based/fiber-based SBS and the technique of scaning-reciever,and it can offer a frequency measurement range of 9~38GHz and a high precision of <1MHz.In the dissertation,we have studied the fiber-based and integrated microwave photonic signal processing.In the past 30 years,both the research community and the commercial sector have paid a heavy attentation on the integrated microwave photonic signal processing.A bright and challenging future is waiting for it.At last,further works on broadband microwave photonic signal manipulation and processing should be done in the future,which is highly expected by 5G communications,broadband wireless access network.