Characteristics And Application Of Silicon Micro-ring Resonators

Miniaturization, integration and scale of the waveguide devices have become the core of modern photoelectric information technology development. The silicon on insulator (SOI) can be used as the effective materials of a micro-ring resonator (MMR) because of the large refractive index difference and strong electromagnetic fields constraint. The SOI micro-ring resonator is featured with a high quality factor, small size, high sensitivity, ease of integration and so on. Its nano-sized planar waveguide structure has been widely used to form various functional devices, including filters, sensors, delay lines, the logic gate, modulators, buffers, lasers, wavelength division multiplexers and so on. It is very suitable for large-scale optoelectronic integrated system. Furthermore, the resonance effect sensitivity of the MMR can be improved in terms of sensing applications.This article mainly studies the MMR’s transmission characteristics, delay characteristics and sensing applications in the application background of filters, sensors and slow light effect. The main aspects are listed as follows.It begins with the brief introductions of MRR, including development status, manufacturing processes, classification, applications, and this article’s background.The theoretical basis of the MRR is studied based on coupled mode theory. Parametric models of the all-pass and add-drop MRR are established by deriving the coupling relationship between the straight and curved waveguide. The main parameters of the device such as extinction ratio and quality factor are also given here.The theoretical basis of multi-MRR is studied based on coupled mode theory through the transfer matrix method and analysis of coupling relationship between curved waveguides. Parametric models of the multi-MRR and array MRR are resolved on the basis of a single MRR. The transmission characteristics of the array MRR are researched from the following four aspects:serial ring numbers, parallel ring numbers, rows parity and column spacing.The influence of serial ring numbers to the resonator’s delay characteristics is analyzed. Then the delay characteristics of a single and series MRR are researched respectively from the following two aspects:the coupling coefficient, transmission coefficient. Degenerate phenomenon of the multi micro-ring is found.The temperature sensing applications of MRR is studied deeply by using the resonant drift effects. It can be concluded that the change in temperature will change the MRR’s effective refractive index and then lead to the resonance wavelength variation. Thus, the relationship between resonance wavelength and temperature can be obtained. The resonance wavelength of add-drop MRR (10μm radius) is calculated at different temperature. The resonance wavelength varies about 100.73 pm/K within 50K temperature range. Based on the above relationships, further research about the influence of effective index and transmission coefficient on temperature sensitivity is made. The input and output coupling structure of MRR is also studied, that is to use vertical coupling grating and adiabatic tapered waveguide with high coupling efficiency. Finally, the general production process and correlation technique of MRR is introduced, including electron beam lithography, dry etching process, silicon oxide growth and so...