Apodized Gratings for Polymeric Waveguide Tunable Wavelength Filters in the manufacturing method

摘要

The present invention proposes a polymer Bragg reflection filter having an ephodazed lattice structure in order to realize a low-cost, compact variable wavelength filter for use in a WDM optical communication system. A cladding formation step of forming a coated lower cladding on a substrate; And forming a Bragg grating on the lower cladding using a laser interferometer to grasp the Bragg grating; And a shadow mask on the grating region on the Bragg grating; And forming an epitaxial lattice in which after the fixing step, the depth of the etched lattice gradually decreases from the center of the lattice region exposed from the oxygen plasma to both sides, thereby forming a lattice; The etch depth can be gradually changed along the direction by forming the epitaxial lattice by the lattice exposed by the oxygen plasma. In order to obtain a high reflectance in a short lattice, an optical waveguide having a large difference in refractive index between the core and the cladding was fabricated. In order to solve the wide bandwidth problem that occurs in a uniform lattice structure, we proposed an epitaxial lattice structure in which the depth of the lattice structure changes slowly along the direction of the light wave. The shadow mask can be used to form an epodized lattice on a polymer optical waveguide. A narrow band width and high reflectance can be confirmed by the polymer Bragg grating wavelength filter fabricated in this way. Also, it was confirmed that when the micro heater was heated, the filtering wavelength was shifted to the short wavelength side. Therefore, the high reflectance reduces the signal loss due to the filter, and the narrow bandwidth can prevent the crosstalk due to the wavelength signal of the adjacent channel in the WDM optical communication system. In addition, it is possible to perform filtering by reflecting a specific wavelength signal among multiplexed and transmitted signals. The excellent variable wavelength characteristic possessed by the polymer Bragg element enables selection of a specific wavelength signal over a wide wavelength range.;