Semiconductor optical integrated device

A device comprising:

• a mesa stripe structure in a stripe shape extending in a first direction, the mesa stripe structure having a first portion and a second portion spaced apart and arranged in the first direction, the mesa stripe structure having a third portion between the first portion and the second portion, the mesa stripe structure comprising a semiconductor;
• and
• an electrode pattern including a first electrode that overlaps with the first portion but does not overlap with the second portion, the electrode pattern including a second electrode that overlaps with the second portion but does not overlap with the first portion, the first electrode and the second electrode being separated, the electrode pattern comprising a metal in a shape of not overlapping with the third portion,
• the electrode pattern including:
• a third electrode that is separated from the first electrode and the second electrode,
• wherein the third electrode is not electrically connected to the mesa stripe structure, and
• wherein the third electrode is configured to relieve unevenness of stress on the mesa stripe structure;
• and
• an adjacent area, that is part of the third electrode, not overlapping with the mesa stripe structure, the adjacent area being next to the third portion in a second direction orthogonal to the first direction, the adjacent area being on a semiconductor layer continuous to the mesa stripe structure.

A method, comprising:

• operating an optical integrated device, wherein the optical integrated device comprises:
• a mesa stripe structure in a stripe shape extending in a first direction, the mesa stripe structure having a first portion and a second portion spaced apart and arranged in the first direction, the mesa stripe structure having a third portion between the first portion and the second portion, the mesa stripe structure comprising a semiconductor;
• and
• an electrode pattern including a first electrode that overlaps with the first portion but does not overlap with the second portion, the electrode pattern including a second electrode that overlaps with the second portion but does not overlap with the first portion, the first electrode and the second electrode being separated, the electrode pattern comprising a metal in a shape of not overlapping with the third portion,
• the electrode pattern including:
• a third electrode that is separated from the first electrode and the second electrode,
• wherein the third electrode is not electrically connected to the mesa stripe structure, and
• wherein the third electrode is configured to relieve unevenness of stress on the mesa stripe structure;
• and
• an adjacent area, that is part of the third electrode, not overlapping with the mesa stripe structure, the adjacent area being next to the third portion in a second direction orthogonal to the first direction, the adjacent area being on a semiconductor layer continuous to the mesa stripe structure.