Study Of Tunable Bragg Grating Based On Nanoimprinting

Modern society is developing very fast, which need us to transport and process the increasing information as soon as possible. Bragg grating, which has function of frequency selection, diffraction, reflection and so on, can be made into photonic interfaced devices and play an important role in optical communication system.Application and current development of polymeric waveguide Bragg grating are firstly studied in this dissertation, including methods of rectangle waveguide analysis, such as effective index method (EIM) and Marcatili approximate analytic method, the basic theory of polymeric waveguide Bragg grating is also introduced. The waveguide Bragg grating is designed and simulated with Rsoft while considering the properties of waveguide grating and materials, dimensions are defined, simulation result is got. To get a better thermo-optical tunable waveguide grating, ZPU series polymer are used as material, which has appropriate thermo-optical coefficients. Traditional micro-processing technologies such as RIE, UV lithography and AL film baking are studied, especially the grating etching process after nano-imprinting, and finally find the best parameters. Two kinds of waveguide Bragg grating are made, using ZPU44 and SiO2 as sub cladding respectively. Heating electrodes are fabricated on the top of up cladding, thermo-optical tunable central wavelengths are achieved by driving voltage on electrodes.Besides, an intact test system is built on quakeproof platform with wavelength test system, optical circulator, polarization maintaining fiber, detectors, and the input and output of the two kinds of waveguide Bragg grating are tested by this system. The thermo-optical tunable chips are tested while driving voltage on electrodes.As the results shows that, the central wavelength of polymer waveguide Bragg grating using SiO2 as sub cladding is around 1553nm,3dB bandwidth is 0.86nm, tunable central wavelength from 1552.98nm to 1546.82nm is realized while tuning driving voltage from OV to 20V. Tuning wavelength scale is 6.16nm. Central wavelength of polymer waveguide Bragg grating using SiO2 as sub cladding is around 1545nm,3dB bandwidth is 0.12nm, tunable central wavelength from 1546.88nm to 1525.25is realized while tuning driving voltage from OV to 20V. Tuning wavelength scale is 21.63nm. The transmission, reflection, thermo-optical tuning test results matched the design results very well, which is a very positive influence to the next study of tunable Bragg gratting.