52results about How to "Good frequency selection characteristics" patented technology

The invention discloses a photonic crystal wavelength division multiplexer. The photonic crystal wavelength division multiplexer adopts the structure of a two-dimensional photonic crystal with triangular crystal lattices, and comprises a photonic crystal input straight waveguide, a 60-degree oblique waveguide, photonic crystal microcavities and photonic crystal output straight waveguides, whereinan optical signal is input through the photonic crystal input straight waveguide and forms the 60-degree oblique waveguide in the direction of a regularly triangular 60-degree angle after transversely transmitting for about tens of periods; two or three holes are removed at the positions close to the transverse direction of the 60-degree oblique waveguide at the interval of three holes to form the photonic crystal microcavities; then other holes in the rows are removed to form the photonic crystal output straight waveguides after two or three holes are remained, so as to form a curved waveguide-microcavity-straight waveguide structure; and 10 to 20 rows of holes are formed between every two microcavity-straight waveguide structures at intervals. In the invention, the photonic crystal straight waveguides, the curved waveguides and the photonic crystal microcavities are coupled to achieve filtering and select signals with specific wavelengths to serve a wave division function.