Research On Micro-nano Optical Resonator Based Bio Chemical Sensing Technology

Photonic integration technology is one of the most promising and cutting-edge research areas which is the major technology of high speed large capacity information network technology. Research on photonic integrated device will promote the rapid development of the photonic integrated industry. Compared with the Optical-Electrical-Optical (OEO) discrete devices, photonic integrated devices have widely application due to their compact structures and excellent performance. There are many key technologies need to be solved, such as, how to prepare multiple photonic devices with different materials on multiple film dielectric layers; how to improve chip integration and performance. Meanwhile, the chip packaging, industrial production and system stability also need to be solved. The research programs and application potentialities of Silicon Photonics have impelled the developments in photonic integrated industry. SOI based mico-nano optical resonators with high Q factor are the basic structures of the optoelectronic and photonic device, can be used as highly integrated and sensitivity sensing structures.In this paper, mico-nano optical resonators based sensing technologies are studied. Its potential applications in biochemical sensing are also investigated. The main research contents and research achievements are as follows(1) The transmission spectra and phase responses of silicon-based microring resonator with different radii and whispering gallery mode (WGM) are studied. With the rising of microring radius, the critical coupling gaps of adjacent resonance peak are close to each other, and Q factors of resonance peak increase. There are three different coupling status: over coupling, critical coupling and under coupling. Q factors of resonance peak increase with the increase of m and Wgap. Silicon-based micro-nano resonators exhibit vulnerability to temperature changes due to the high thermo-optic coefficient (TOC) and thermal expansion coefficient (TEC) of silicon.Resolutions to this problem can be classified into two categories: "athermal" solutions and "control-based" solutions.(2) The bidirectional transmission characteristics and coupling status of the angular grating-microring (AG-MRR) are investigated, and the wavelength-selective characteristic of angular grating is demonstrated by using the effective-index method(EIM). The quasi-FSR is around 50.2 nm which enlarges the measurement range. The small size of the AG-MRR makes it easy to integrate with other SOI devices as an integrated sensor with ultra-large measurement range.(3) In order to solve the influence of temperature on the micro-nano resonator,we proposed a microdsk with two WGM as a dual-parameter measurement of refractive index (RI) and temperature. The propagation characteristics, coupling status and waveguide sensitivity of the WGM (1, 28) and WGM (0,36) are investigated. By using the sensing characteristic matrix, the RI and temperature changes can be calculated by the resonant wavelength changes of the WGM (1, 28) and WGM (0,36),which can achieve simultaneous measurement of RI and temperature.(4) The temperature compensation of silicon-based microdisk by using negative TOC materials (e.g. polymer). The two-layer dielectric microdisk contains two dielectric layers which are silicon and polymethylmethacrylate (PMMA). The results show that the temperature sensitivity of microdisk decreases with the increase of the negative TOC layer thickness. However, the temperature sensitivity is nearly invariable when the thickness beyond the 100 nm. Meanwhile, the RI sensitivity changes similar with temperature sensitivity. The microdisk sensor by using TE01 has lower RI sensitivity than that by using TM01, and has higher temperature sensitivity than that by using TM01. The compensation of the negative TOC PMMA layer to the TM01 is more effective than the TE01, which provide the studying foundation for the temperature compensation.(5) Due to the local field enhancement of surface plasmon polaritons (SPPs), the interaction between the light and matter is enhanced. The two-layer dielectric loaded surface plasmon polaritons (TDLSPPs) waveguide based microring resonator is proposed as a biochemical sensor. The effective index, propagation length and waveguide sensitivity of the TDLSPPs microring resonator are optimized with different structure parameters. The results show that the t2 and t are chosen as 700nm and 280nm. The propagation length of the mode in the TDLSPPs microring resonator is 126 ?m. Q factor and ER are 541.2 and 12.2 dB, respectively. The RI sensitivity and detection limit (DL) are 408 nm/RIU (which is six times of that in conventional microring resonator) and 2.13×10-4RIU, respectively. When the TDLSPPs microring is used as a glucose solution sensor, the RI sensitivity and detection limit (DL) are 260 nm/RIU and 6.97×10-5RIU, respectively.The micro-nano optical resonator is the foundation of silicon photonic integration, and provides a feasible scheme for the high integration and high sensitive biochemical sensor. The research results has a certain guiding significance for the Lab-on-chip, and will be expected to be widely used in the developing of the In-vitro Diagnostic (IVD) and Point-of-care Testing (POCT) equipments.