Abstract: A semiconductor laser (1) emits laser light. An electro-absorption optical modulator (2) modulates the laser light. The electro-absorption optical modulator (2) includes a plurality of electro-absorption regions (2a, 2b, 2c) having different extinction characteristics, whereby the extinction ratio curve of the optical device can be controlled to have a shape with multiple steps that is suited to driving conditions.

Abstract: A semiconductor laser (1) emits laser light. An electro-absorption optical modulator (2) modulates the laser light. The electro-absorption optical modulator (2) includes a plurality of electro-absorption regions (2a, 2b, 2c) having different extinction characteristics, whereby the extinction ratio curve of the optical device can be controlled to have a shape with multiple steps that is suited to driving conditions.

Abstract: This 2-pyridone compound represented by formula [1] or a tautomer of said compound, or a pharmaceutically acceptable salt of said compound or said tautomer, or a solvate of said compound or the like has a superior GK-activating effect and is useful as a pharmaceutical.

Abstract: This 2-pyridone compound represented by formula [1] or a tautomer of said compound, or a pharmaceutically acceptable salt of said compound or said tautomer, or a solvate of said compound or the like has a superior UK-activating effect and is useful as a pharmaceutical.

Abstract: A 2-pyridone compound represented by the formula [1]: {wherein in the formula [1], the ring represented by A represents a benzene ring or a pyridine ring, X represents any of the structures represented by the formulas [3] shown below: V represents a single bond or a lower alkylene group, and W represents a single bond, an ether bond or a lower alkylene group (wherein the lower alkylene group may contain an ether bond)}, a tautomer or stereoisomer of the compound, a pharmaceutically acceptable salt thereof, or a solvate thereof is a compound that has an excellent GK activating effect and is useful as a pharmaceutical.

Abstract: A 2-pyridone compound represented by the formula [1]: {wherein in the formula [1], the ring represented by A represents a benzene ring or a pyridine ring, X represents any of the structures represented by the formulas [3] shown below: V represents a single bond or a lower alkylene group, and W represents a single bond, an ether bond or a lower alkylene group (wherein the lower alkylene group may contain an ether bond)}, a tautomer or stereoisomer of the compound, a pharmaceutically acceptable salt thereof, or a solvate thereof is a compound that has an excellent GK activating effect and is useful as a pharmaceutical.