Design Of Athermal Waveguide Micro-ring Based On All-polymer Materials And Fabrication Of Substrate

Polymer with its low cost, the refractive index can be controlled, simple preparation tec hnology, flexible integration and other advantages has been made optical waveguide device, polymer device research being focused in rent years. The polymer micro-ring in optical filter, high sensitive biochemical optical waveguide sensors will have broad prospect of application. Polymer micro-ring waveguide resonant wavelength are highly susceptible to environmental temperature, thus eliminating the polymer micro-ring waveguide temperature sensitivity is a key problem that must solve in actual application. The paper embarks from the polymer micro ring waveguide temperature sensitivity mechanism, designing the polymer waveguide atherm-alization based on the polymer micro-ring waveguide, conducting polymer substrate material optimization analysis and studying the preparation technology, all of the work are the founda-tion for the athermalization and application of polymer micro-ring waveguide.First of all, analyzing the temperature sensitivity mechanism of polymer micro-ring wave guide, started from the resonance equation of the micro-ring waveguide derived the factors that affecting the temperature sensitivity of micro-ring waveguide, through thermal expansion effect of the substrate to offset the thermal-optic effect of the waveguide, to achieve athermali-zation of the waveguide. Using the polymer substrate instead the traditional silicon substrate, optimizating the thermal expansion coefficient of the substrate to realize the not temperature sensitive device. Comparing a variety of physical and chemical properties of polymer material parameters, choosing the SU-8 and NOA61 as "sandwich" substrate materials.Next measuring the thermal expansion coefficient of SU-8 and NA061 two kinds of polymer material. Prepared body material of SU-8 and NOA61, used thermal mechanical analyzer (TMA Q400) to measure the thermal expansion coefficient of the two materials, got the thermal expansion coefficient of SU-8 was α=4.9995×10-5/K, the thermal expansion coefficient of NOA61 was α=2.36187×10-4/K, provided the basis for the design of each layer’s thickness of the "sandwich" substrate structure.Then experimental studied the SU-8 and NOA61 two kinds of polymer film forming process, emphasis was on the spin speed and coated time of the film, curing temperature and time, and the influence of process parameters on the film thickness, by optimizing the process parameter, obtained the rule of the spin coating film and the process parameters of film thick -ness controlling. The controlling precision of the thickness of the SU-8 relative to the speed is 6-3.4nm/rpm, the controlling precision of the thickness of the SU-8 relative to the spin time is 50nm/s; The controlling precision of the thickness of the NOA61 relative to the speed is 13.3nm/rpm, the controlling precision of the thickness of the SU-8 relative to the spin time is l00nm/s. At the same time studied the multilayer film forming technology, including the curing and film adhesion between SU-8、NOA61 and waveguide material PSQ, the work were the foundation for athermalization micro-ring waveguide preparation.