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Optical Waveguide Biosensors Based On Silicon-on-Insulator Platform

Posted on:2016-03-29Degree:DoctorType:Dissertation
Country:ChinaCandidate:X X JiangFull Text:PDF
GTID:1108330464954337Subject:Optical Engineering
Abstract/Summary:Request the full-text of this thesis
Biosensors have seen great advances due to its applications in many fields, such as medical diagnosis, drug development, environmental monitoring, food quality control and so on. Among them, optical biosensors have received great interest in the past few years for its various advantages such as high sensitivity, immune to electromagnetic interference, ultra-compactness, high flexibility etc. Besides, high speed computing and high bandwidth communication have promoted the development of silicon photonics. A variety of devices on silicon-on-insulator platform have been demonstrated with high performance and currently are on the way to industrial applications. The subject of this thesis is focused on developing high performance optical sensors based on silicon photonics waveguides.The first part of this thesis is to develop highly sensitive refractive index sensors based on silicon waveguides. Firstly, the fabrication of silicon nanowire wavegudes based on the electron beam lithorgraphy was systematically investigated. And we experimentally deomonstrated an ultrahigh-sensitivity silicon nanowire wavegude sensor based on cascaded double-ring resonators operating in TM mode. We also show that an array of cascaded double-ring sensors can be realized by using WDM approach. Secondly, we present another ultrahigh sensitivity sensor based on cascaded Mach-Zehnder interferometer (MZI) and ring resonator with Vernier effect using wavelength interrogation. Besides, analysis and comparison between the cascaded double-ring sensor and MZI-ring sensor were also carried out in terms of detection limits and temperature drifts. Lastly, we investigated the biosensing application of the MZI-ring sensor. By employing surface functionalization and monitoring the interaction between goat and antigoat IgG pairs, we show that this high performance sensor is promising for medical diagnosis and other biosensing applications.The second part of this thesis is to explore the Raman spectroscopic sensor based on silicon nanowire waveguides. Traditional Raman spectrometers are always bulky and suffer from poor efficiency of signal collection. Here we proposed a novel Raman spectroscopic sensor which employs silicon nanowire waveguides for excitation and collection of Raman signal and an integrated micro-ring resonator as a filter. Theoretical calculations and preliminary experimental results indicate that this integrated sensor has the potential to detect Raman signal with low frequency.
Keywords/Search Tags:Optical sensor, Ring resonator, Mach-Zehnder interferometer, Vernier effect, SOI nanowire waveguide, Raman spectroscopy, Biosensing
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