Optical semiconductor device having a shield wire and optical pickup device having a shield wire

An optical pickup device performing at least one of operations including reading of data from an optical disk medium and writing of data to an optical disk medium, said optical pickup device comprising:

• a laser beam generating unit operable to irradiate the optical disk medium with a laser beam;
• and
• an optical semiconductor device which receives the laser beam radiated by said laser beam generating unit and reflected by the optical disk medium,
• wherein said optical semiconductor device includes:
• a light-receiving element which converts light into an electric signal;
• an amplifier circuit having an input to which said light-receiving element is connected, and which amplifies the electric signal;
• a connection wire to which the signal amplified by said amplifier circuit is outputted;
• an output circuit having an input to which said connection wire is connected, which performs current amplification on the signal amplified by said amplifier circuit and outputs the current-amplified signal to an output terminal;
• a feedback resistor connected between the input of said amplifier circuit and the output terminal;
• and
• a shield wire connected to a potential outputted from said output circuit or a potential resulting from a voltage follower of the potential outputted from said output circuit,
• wherein the potential connected to the shield wire is in phase with the signal outputted to the connection wire.