| As the third generation of semiconductor material.GaN plays an important role in modern optical communication systems.The LEDs made of GaN have the advantages of large forbidden band width,high luminous efficiency and fast frequency response.GaN plays a crucial role on the development of information society.At the same time,with the more researches on using InGaN / GaN multi-quantum well devices as photodetectors,the researches of visible light communication chip of integrated GaN light source,optical waveguide and photodetector are becoming more popular.In this paper,we mainly study different waveguide structures that connect LED light source and photodetector in the communication chip of visible light,propose different connection structures including directional coupling structure,beam splitter structure and reflective structure,and sumilate the optical coupling properties of the waveguide by the Rsoft software's BeamProp and FDTD numerical analysis function.The high refractive index difference between GaN and air makes the structure of waveguide with a strong optical field limit function.The main technologies witch are used to realize the suspended monolithic homogeneous integration of InGaN / GaN multiple quantum well light source,optical waveguide and photodetector such as UV lithography,inductive ion coupling etching,deep silicon etching,electron beam evaporation and rapid annealing are studie.We use deep-silicon etching and back-thinning double-sided etching technology to achieve the suspended structure.After that,the roughness of the structures were tested and analyzed by means of optical microscope,scanning electron microscope(SEM)and atomic force microscope(AFM).Finally,using high-speed signal generator,oscilloscope and network vector analyzers and other instruments to test the communication performance of integrated communication chip. |
