Optical semiconductor element

An optical semiconductor element comprising:

• a substrate;
• a first ridge formed on the substrate and having a first first-conductivity-type cladding layer, a first core layer, a first second-conductivity-type cladding layer, and a first contact layer in this order from a lower side, with first ridge grooves provided on both lateral sides of the first ridge;
• a first electrode formed on the first ridge without spreading to, or being electrically connected by way of, the first ridge grooves, the first electrode including a first solder layer, wherein the first electrode is formed in contact with the first contact layer;
• a second ridge formed on the substrate and contiguous to the first ridge, the second ridge having a second first-conductivity-type cladding layer, a second core layer, a second second-conductivity-type cladding layer, and a second contact layer in this order from a lower side, with second ridge grooves provided on both lateral sides of the second ridge;
• and
• a second electrode formed in contact with the second contact layer, on the second ridge, and having a spreading portion spreading over the second ridge grooves, the second electrode including a second solder layer, wherein
• the second core layer is an active layer that emits a laser beam, and
• the first core layer is an absorption layer that modulates the laser beam from the second core layer.