OPTICAL OSCILLATION DEVICE AND RECORDING APPARATUS

摘要

Provided is a recording apparatus including a self-excited oscillation semiconductor laser that has a double quantum well separate confinement heterostructure and includes a saturable absorber section to which a negative bias voltage is applied and a gain section into which a gain current is injected, an optical separation unit, an objective lens, a light reception element, a pulse detection unit, a reference signal generation unit, a phase comparison unit, a recording signal generation unit, and a control unit.

主权项

1. A recording apparatus comprising:
a self-excited oscillation semiconductor laser that has a double quantum well separate confinement heterostructure and includes a saturable absorber section to which a negative bias voltage is applied and a gain section into which a gain current is injected; an optical separation unit that separates an oscillated light beam from the self-excited oscillation semiconductor laser into two oscillated light beams; an objective lens that condenses one of the separated oscillated light beams on an optical recording medium; a light reception element that receives the other of the oscillated light beams separated by the optical separation unit; a pulse detection unit that detects a pulse of the oscillated light beam received by the light reception element; a reference signal generation unit that generates a master clock signal; a phase comparison unit that calculates a phase difference between the master clock signal and the pulse; a recording signal generation unit that generates a recording signal using a negative voltage at a timing of the master clock signal and applies the recording signal as the negative bias voltage to the saturable absorber unit of the self-excited oscillation semiconductor laser; and a control unit that controls an oscillation frequency of the self-excited oscillation semiconductor laser by changing the gain current to be injected into the gain section of the self-excited oscillation semiconductor laser or the negative bias voltage to be applied to the saturable absorber unit based on the phase difference.