Photonic Generation Of Ultra-wide Band Radio Based On Semiconductor Laser Dynamic

As one of the research contents of the Microwave Photonics, photonic assistant Ultra-wide band (UWB) signals generation is an issue of concern within the whole international and domestic academic circle. It is not only considered as the most direct and efficient way for generating the high frequency band (for example,10-60 GHz) UWB signal with arbitrary waveform because of the reasonable elusion for the electronic bottleneck by virtue of processing the signals in optical domain, but also could combine with the radio over fiber link for distributing the optical UWB signals, afterward compensate the drawback of the UWB signals'short coverage radius. This dissertation studied several issues in technologies about photonic UWB signals generation and spectrum characteristics control and its contributions are summarized as follows:Firstly, we analyze and compare the existing optical UWB generation technologies, point out that regardless of the baseband or mm-wave UWB signals generation, the high frequency electronic device is necessary, which means high cost and complexity. In addition, the methods based on Gaussian pulse shaping theory are different to control the spectrum profile of generated pulse, which confines their applications in the complicated environment and obstructs the evolution and combination of the emerging technologies.Secondly, we propose and demonstrate an approach to the generation of UWB pulse utilizing chaotic dynamics of semiconductor laser (SL). The output UWB chaotic optical pulses generated by SL with optical feedback can be controlled when the feedback strength and driving current of the SL were tuned. The experimental results are well consistent with the simulated results based on the laser's rate equations. Moreover, through external light injecting the original chaotic source, our experimental obtain the UWB pulses with ideal spectrum profile which could satisfy the Federal Communications Commission regulations or avoid the overlay spectrum band between UWB and Wireless-Fidelity systems by adjusting the injecting detuning.Thirdly, we pay attention to the combination of cognitive radio and UWB over fiber for the first time. We proposed and demonstrated an approach to generate the UWB signal based on the period-one state of optically injected laser diode (OILD). Transmission of the UWB signal over 10 km SMF is realized. By adjusting the injection strength or the slave light's wavelength, the center frequency of generated UWB signal could be tuned over widely range, as well as the line spacing of the signals could be changed by controlling the pulsing frequency. Such findings are of great potential for applications in cognitive-UWB-over-fiber system, because flexible frequency conversion makes it convenient to realize dynamic spectrum accessing.Finally, in this thesis we summarize our discoveries and provide discussion on the possible future research issues.