Short Carbon Nanotube Nano-Film-Based Polymer/SiO2 Hybrid Waveguide Micro-Ring Filter

A polymer/SiO2 hybrid waveguide micro-ringfilter basedon a short carbon nanotube (CNT) nano-film is presented. The nano-filmis coated on the top surface of the polymer waveguide, and both thenano-film and polymer waveguide serve as the core of the device. Thefilm can effectively improve the coherent depth and quality factorvalues of the filter. Due to the excellent light absorption characteristicand large thermo-optic effect of the CNT nano-film, the filter showsgood all-optical tunable performance. Experimental results show thatits all-optical wavelength tuning efficiency reaches -0.030nm/mW, and it is 1.67 times as much as that of the filter withoutthe nano-film. With the CNT nano-film, its thermal sensitivity reaches25.7 times as much as that of the filter without the film. The deviceshows the advantages of high tuning efficiency, small size, compactstructure, and all-optical control, and it is expected to have potentialapplications in optical filters, optical switches, optical sensors,spectral analysis, and so on.