Investigation On Integrated Polarization Handling Devices And Their Applications In All-Optical Signal Processing

The prosperous development of optical fiber communication technology originates from the breakthroughs of optical transmission technology and optical switching technology. In the field of optical transmission, the developing trend is the combination of more advanced modulation formats and multi-dimensional multiplexing to improve the channel spectrum efficiency. On the other hand, all-optical signal processing and the integration and intelligentialize of optoelectronics devices seem to be the future in the field of optical switching. The integrated optoelectronic devices have less power consumption and complexity and are more stable compared to conventional discrete devices. Thanks to the groun dBreaking achievement in microelectronic technology, the silicon photonics has attracted more and more attention. Researches on optical sources, modulators, photodetectors and optical signal processing devices based on silicon photonics have experienced a remarkable progress in the last few decades.However, the polarization mismatch between optical fiber and integrated photonic circuit has become a severe problem since the footprint of silicon-based devices keeps dropping. To tackle this scientific issue, we analyze and point out polarization diversity method. Next, we elaborate the design, fabrication and measurement of the key components of polarization diversity: polarization beam splitter and polarization rotator. Eventually, we proposed three novel polarization devices and two novel photonic circuit applying for the processing of optical signals. The work of this thesis can be concluded as follows:(1) We analyze the principle of polarization mismatch and we give out a general solution; we carry out a detailed investigation on reported schemes of polarization beam splitter and polarization rotator. And we analyze the principle of these schemes and classify them into several categories;(2) We give an explicit description of the design, fabrication and measurement of typical polarization beam splitter and polarization rotator. And reasonable experimental results are obtained;(3) We propose three novel polarization handling devices. The first one is a novel polarization rotator that is fabrication tolerant. The second one is a power splitter for specific polarization mode with large operational bandwidth. Compared to conventional schemes based on directional couplers, the performance of our device has been improved dramatically. The last one is a novel polarization rotator that works on first order mode instead of fundamental mode that most of previous schemes have been concentrating on.(4) We propose two integrated photonic circtuits. The first one is a novel polarization insensitive filter that is the combination of microring resonator and 2D photonic grating coupler. The all-optical filtering of wavelength division multiplexing and polarization division multiplexing(WDM-PDM) signal can be optained. The second one is a novel reconfigurable add/drop filter that can process signal both on wavelength and polarization domain.