Light oscillation device and recording device

A recording device comprising:

• a light oscillation device having a self oscillation semiconductor laser that has a double quantum well separated confinement heterostructure made of GaInN/GaN/AlGaN materials and that includes a saturable absorber section which is applied with a negative bias voltage and a gain section into which a gain current is injected;
• a light separation means for separating a portion of laser light beams from the self oscillation semiconductor laser;
• a light sensing element that senses the laser light beams separated by the light separation means;
• and a current control circuit which controls a current injected into the gain section of the self oscillation semiconductor laser based on an amount of the laser light beams which are sensed by the light sensing element;
• a light modulation means for modulating the laser light emitted from the light oscillation device;
• an object lens that collects the laser light modulated by the light modulation means on a recording medium;
• a reference signal generation unit that generates master clock signals;
• a recording signal generation unit that generates recording signals based on the master clock signals;
• a driving circuit that drives the light modulation means based on the recording signals;
• a pulse detection means for detecting pulsed light of the laser light sensed by the light sensing element;
• a phase comparison means for detecting a phase difference between the pulsed light and the master clock signals;
• and
• a compensation means for controlling a voltage applied to the saturable absorber section of the self oscillation semiconductor laser based on the phase difference detected by the phase comparison means.

A recording device comprising:

• a light oscillation device having a self oscillation semiconductor laser that has a double quantum well separated confinement heterostructure made of GaInN/GaN/AlGaN materials and that includes a saturable absorber section which is applied with a negative bias voltage and a gain section into which a gain current is injected;
• a light separation means for separating a portion of laser light beams from the self oscillation semiconductor laser;
• a light sensing element that senses the laser light beams separated by the light separation means;
• and a current control circuit which controls a current injected into the gain section of the self oscillation semiconductor laser based on an amount of the laser light beams which are sensed by the light sensing element;
• a frequency separation means connected to the saturable absorber section of the self oscillation semiconductor laser;
• a light modulation means for modulating the laser light emitted from the light oscillation device;
• an object lens that collects the laser light modulated by the light modulation means on a recording medium;
• a reference signal generation unit that generates master clock signals;
• a recording signal generation unit that generates recording signals based on the master clock signals;
• a driving circuit that drives the light modulation means based on the recording signals;
• a frequency detection means for detecting a frequency of the signal detected by the frequency separation means;
• a frequency comparison means for detecting a frequency difference between the frequency detected by the frequency detection means and a frequency of the master clock signals;
• and
• a compensation means for controlling a voltage applied to the saturable absorber section of the self oscillation semiconductor laser based on the frequency difference detected by the frequency comparison means.

A light oscillation device comprising:

• a self oscillation semiconductor laser that has a double quantum well separated confinement heterostructure made of GaInN/GaN/AlGaN materials and that includes a saturable absorber section which is applied with a negative bias voltage and a gain section into which a gain current is injected;
• a light separation unit that separates a portion of laser light beams from the self oscillation semiconductor laser;
• a light sensing element that senses the laser light beams separated by the light separation unit;
• and
• a current control circuit which controls a current injected into the gain section of the self oscillation semiconductor laser based on an amount of the laser light beams which are sensed by the light sensing element.

A recording device comprising:

• a light oscillation device having a self oscillation semiconductor laser that has a double quantum well separated confinement heterostructure made of GaInN/GaN/AlGaN materials and that includes a saturable absorber section which is applied with a negative bias voltage and a gain section into which a gain current is injected;
• a light separation unit that separates a portion of laser light beams from the self oscillation semiconductor laser;
• a light sensing element that senses the laser light beams separated by the light separation unit;
• and a current control circuit which controls a current injected into the gain section of the self oscillation semiconductor laser based on an amount of the laser light beams which are sensed by the light sensing element;
• a light modulation unit that modulates the laser light emitted from the light oscillation device;
• an object lens that collects the laser light modulated by the light modulation unit on a recording medium;
• a reference signal generation unit that generates master clock signals;
• a recording signal generation unit that generates recording signals based on the master clock signals;
• a driving circuit that drives the light modulation unit based on the recording signals;
• a pulse detection unit that detects pulsed light of the laser light sensed by the light sensing element;
• a phase comparison unit that detects a phase difference between the pulsed light and the master clock signals;
• and
• a compensation unit that controls a voltage applied to the saturable absorber section of the self oscillation semiconductor laser based on the phase difference detected by the phase comparison unit.

A recording device comprising:

• a light oscillation device having a self oscillation semiconductor laser that has a double quantum well separated confinement heterostructure made of GaInN/GaN/AlGaN materials and that includes a saturable absorber section which is applied with a negative bias voltage and a gain section into which a gain current is injected;
• a light separation unit that separates a portion of laser light beams from the self oscillation semiconductor laser;
• a light sensing element that senses the laser light beams separated by the light separation unit;
• and a current control circuit which controls a current injected into the gain section of the self oscillation semiconductor laser based on an amount of the laser light beams which are sensed by the light sensing element;
• a frequency separation unit connected to the saturable absorber section of the self oscillation semiconductor laser;
• a light modulation unit that modulates the laser light emitted from the light oscillation device;
• an object lens that collects the laser light modulated by the light modulation unit on a recording medium;
• a reference signal generation unit that generates master clock signals;
• a recording signal generation unit that generates recording signals based on the master clock signals;
• a driving circuit that drives the light modulation unit based on the recording signals;
• a frequency detection unit that detects a frequency of the signal detected by the frequency separation unit;
• a frequency comparison unit that detects a frequency difference between the frequency detected by the frequency detection unit and a frequency of the master clock signals;
• and
• a compensation unit that controls a voltage applied to the saturable absorber section of the self oscillation semiconductor laser based on the frequency difference detected by the frequency comparison unit.