Study On Micro-ring Resonator Sensor With Cascaded Reflection Structure

In recent years,photonic integration technology has played an important role in optical interconnection and intelligent sensing because it can meet the needs of data center interconnection and super-large capacity transmission in trunk lines.Silicon photonic technology is developing rapidly because it is compatible with complementary metal oxide semiconductors(COMS)and has high integration.Micro-ring resonator(MRR)has been used widely in optical sensing and optical communication due to their simple structure and multi-function.This paper mainly studies the sensor based on MRR: the reflective cascaded micro-ring resonant(RCMRR)sensor with high sensitivity was proposed,and the reflective Fabry Perot(FP)etalon cascaded with MRR(REMRR)temperature sensor with high sensitivity was designed and fabricated.Firstly,the performance parameters and sensing principle of the MRR sensor were introduced.The transmission spectrum formulas of MRR and cascaded micro-ring resonant(CMRR)are derived using the transfer matrix method.The reflective MRR(RMRR)and RCMRR with cascaded reflective structures are proposed,and wavelength and intensity interrogation methods are simulated.Secondly,the fabrication process of the sensor chip is introduced,and the chip is integrated and packaged with the optical fiber array.The microfluidic device and temperature control system used in the experiment are designed.Thirdly,the sensing systems for wavelength and intensity interrogation methods are established,and the equalization sensing and temperature sensing of CMRR sensors are tested.The experimental results show that the sensitivity of CMRR sensor is about 16.24 times that of MRR due to vernier effect,and the temperature sensitivity of wavelength interrogation and intensity interrogation are 1.1105nm/℃ and 0.5028 d B/℃ respectively.Fourthly,experimental detection of the RMRR transmission spectrum was carried out,and the reason why the ideal transmission spectrum was not detected was analyzed.A kind of waveguide ring reflection structure was proposed,and the mask for RMRR and RCMRR sensors were designed.Fifthly,the wavelength and intensity interrogation of RCMRR sensor are simulated.The simulation results show that the sensitivity of RCMRR sensor with specified parameters is 2.96 times that of CMRR sensor during intensity interrogation.Finally,the REMRR temperature sensor is proposed and verified by experiments.The experimental results show that the wavelength interrogation sensitivity is 1.7 times that of the CMRR temperature sensor,and the intensity interrogation sensitivity is 3.87 times that of the CMRR temperature sensor.