Optical recording head device, optical recording apparatus, and recording method

An optical recording apparatus comprising:

• an optical recording head device comprising a light source configured to output a relaxation oscillation optical pulse with a duration between a first time when a first amplitude is half of a peak amplitude of a single pulse and a second time when a second amplitude is half of the peak amplitude of the single pulse 820 ps or shorter, a driver configured to drive the light source, an objective lens configured to converge an emitted light from the light source on a recording layer of a recording medium, and to capture a reflected light from the recording layer of the recording medium, a distributor placed between the light source and the objective lens, configured to distribute an incident light, and a photo-detector configured to detect the reflected light via the distributor;
• an arithmetic module configured to perform an arithmetic operation of a reproduction signal, based on a signal from the photo-detector;
• and
• a controller configured to control the driver and the arithmetic module,
• wherein a resonator length of the light source is 6560 μm or shorter, and the relaxation oscillation pulse with a cycle in a range of between one cycle and three cycles is configured to raise a temperature of the recording layer to a level above a melting point in order to record a mark.

A recording method by an optical recording apparatus comprising a light source with a resonator length of 6560 μm or less, comprising:

• generating a driving current set at a level lower than a threshold level of a current of the light source;
• inputting the driving current to the light source, and driving the light source;
• and
• increasing the driving current to a peak current level for a predetermined time, and outputting a relaxation oscillation optical pulse from the light source with a duration between a first time when a first amplitude is half of a peak amplitude of a single pulse and a second time when a second amplitude is half of the peak amplitude of the single pulse 820 ps or shorter,
• wherein the increasing and outputting comprise causing the light source to output the relaxation oscillation pulse with a cycle in a range of between one cycle and three cycles of relaxation oscillation, and raising the temperature of the recording layer to a level above a melting point in order to record a mark.