Abstract: An aluminum alloy sheet which is high in strength and excellent in heat conductivity, and which can be given an anodic oxide coating with a white color and a suitable yellowishness is provided. An aluminum alloy ingot containing Mg: 0.80 to 1.8 mass %, Fe: 0.05 to 0.30 mass %, Si: 0.20 mass % or less, Cu: 0.03 to 0.15 mass %, Mn: 0.05 to 0.20 mass %, and Cr: 0.05 to 0.15 mass %, restricts Zn to less than 0.15 mass %, and balance of Al and unavoidable impurities is treated by holding it at 560 to 620° C. for 1 to 5 hours, then hot rolled and, either through or not through process annealing, and cold rolled by a final cold rolling reduction of 15 to 95% to obtain an aluminum alloy sheet which has a 0.2% yield strength of 180 MPa or more and a conductivity of 40 (IACS %) or more.

Abstract: An aluminum alloy sheet which is high in strength and excellent in heat conductivity, and which can be given an anodic oxide coating with a white color and a suitable yellowishness is provided. An aluminum alloy ingot containing Mg: 0.80 to 1.8 mass %, Fe: 0.05 to 0.30 mass %, Si: 0.20 mass % or less, Cu: 0.03 to 0.15 mass %, Mn: 0.05 to 0.20 mass %, and Cr: 0.05 to 0.15 mass %, restricts Zn to less than 0.15 mass %, and balance of Al and unavoidable impurities is treated by holding it at 560 to 620° C. for 1 to 5 hours, then hot rolled and, either through or not through process annealing,and cold rolled by a final cold rolling reduction of 15 to 95% to obtain an aluminum alloy sheet which has a 0.2% yield strength of 180 MPa or more and a conductivity of 40 (IACS %) or more.

Abstract: An optical modulator includes a p- or n-type semiconductor layer that is provided at an upper part of an optical waveguide path, and modulating electrodes that are provided at intervals on the semiconductor layer in an extension area of the optical waveguide path. The semiconductor layer has first regions located immediately under the modulating electrodes, and second regions located between the first regions. The second regions have separators that electrically separate the first regions from one another.

Abstract: An optical modulator includes a p- or n-type semiconductor layer that is provided at an upper part of an optical waveguide path, and modulating electrodes that are provided at intervals on the semiconductor layer in an extension area of the optical waveguide path. The semiconductor layer has first regions located immediately under the modulating electrodes, and second regions located between the first regions. The second regions have separators that electrically separate the first regions from one another.