2results about How to "High side mode suppression ratio" patented technology

The invention relates to the technical field of semiconductor lasers, in particular to a narrow linewidth laser based on an external cavity grating waveguide and a DFB chip. The high-reflection film is arranged on the left end surface of the DFB laser chip in a plating manner; the first antireflection film is arranged on the right end surface of the DFB laser chip in a plating manner; the grating optical waveguide chip is arranged on the right side of the DFB laser chip, and the left end face of the grating optical waveguide chip abuts against the right end face of the DFB laser chip; the second antireflection film is plated on the left end surface of the grating optical waveguide chip; the third antireflection film is plated on the right end surface of the grating optical waveguide chip; the grating optical waveguide chip comprises a waveguide substrate, and the waveguide substrate is made of an insulating transparent material. The method has the following beneficial effects: 1, the filtering sufficiency and the line width compression effect are remarkable; 2, the advantages of low loss and low power consumption are outstanding; 3, mode regulation and control are flexible, and stability and tunability are both considered; and 4, the compatibility is high.

The application discloses a filter based on a multi-mode subwavelength grating. The filter comprises a mode demultiplexer for multiplexing and demultiplexing of a base mode and a high-order mode, a subwavelength grating for weakly binding regulation of a mode field of the base mode and the high-order mode, and a straight-through waveguide for output of the base mode. The application introduces a structure of the subwavelength grating and weakly binding regulation of the mode field, and by virtue of excellent flat dispersion regulation characteristics, the application realizes apodization of the grating while keeping consistent local refractive index of the grating, thereby obtaining the filter with high side mode suppression ratio and no free spectral range limitation, and the filter can realize flat and low-loss spectral response, meets the next-generation large-capacity and high-speed wavelength division multiplexing transmission demand, and has the advantages of simple structure, simple process, excellent performance and the like.