Self-oscillating semiconductor laser device and driving method thereof

A self-oscillating semiconductor laser device comprising:

• (a) a laminated structure in which a first compound semiconductor layer having a first conductive type and composed of a GaN base compound semiconductor, a third compound semiconductor layer configuring an emission region and a saturable absorption region composed of the GaN base compound semiconductor, and a second compound semiconductor layer having a second conductive type that is different from the first conductive type and composed of the GaN base compound semiconductor are successively laminated;
• (b) a second electrode formed on the second compound semiconductor layer;
• and
• (c) a first electrode electrically connected to the first compound semiconductor layer,
• wherein the second electrode is separated into a first portion to create a forward bias state by passing current to the first electrode via the emission region and a second portion to apply an electric field to the saturable absorption region by a separation groove, and
• the third compound semiconductor layer includes a quantum well structure having a well layer and a barrier layer,
• a region of the second compound semiconductor layer apart from the third compound semiconductor layer is mounted with an electron barrier layer having more than 10 nm thick,
• a distance between the electron barrier layer and the third compound semiconductor layer is 4.5×10−8 m or more and 8×10−8 m or less, and
• there is relationship of (dF/dL)<0 between the self-oscillating frequency F and the mean light output L when the current greater than the current value where kink is occurred in optical output-current characteristics is to be passed to the first portion of the second electrode.

A self-oscillating semiconductor laser device comprising:

• (a) a laminated structure in which a first compound semiconductor layer having a first conductive type and composed of a GaN base compound semiconductor, a third compound semiconductor layer configuring an emission region and a saturable absorption region composed of the GaN base compound semiconductor, and a second compound semiconductor layer having a second conductive type that is different from the first conductive type and composed of the GaN base compound semiconductor are successively laminated;
• (b) a second electrode formed on the second compound semiconductor layer;
• and
• (c) a first electrode electrically connected to the first compound semiconductor layer,
• wherein the second electrode is separated into a first portion to create a forward bias state by passing current to the first electrode via the emission region and a second portion to apply an electric field to the saturable absorption region by a separation groove, and
• the third compound semiconductor layer includes a quantum well structure having a well layer and a barrier layer,
• a region of the second compound semiconductor layer apart from the third compound semiconductor layer is mounted with an electron barrier layer having more than 10 nm thick,
• a distance between the electron barrier layer and the third compound semiconductor layer is 4.5×10−8 m or more and 8×10−8 m or less, and
• there is relationship of (dF/dI)<0 between the self-oscillating frequency F and the current value I to be passed to the first portion of the second electrode when passing the current greater than the current value where kink is occurred in optical output-current characteristics is to be passed to the first portion of the second electrode.