Semiconductor laser element and method of manufacturing the same

A method of manufacturing a semiconductor laser element comprising:

• providing a semiconductor wafer having a substrate and a semiconductor layer formed on a front surface of the substrate;
• forming a plurality of first electrodes on a back surface of the substrate;
• forming a plurality of second electrodes on a front surface of the semiconductor layer;
• forming a plurality of marks configured to allow reading of predetermined information, the plurality of marks being formed in at least one of (i) positions on the surface on which the first electrode is formed, spaced apart from the first electrodes, and (ii) positions on the surface on which the second electrode is formed, spaced apart from the second electrodes, wherein the marks are made of a metal material and have a thickness smaller than a thickness of the electrodes that are formed on the surface on which the marks are formed;
• and
• after forming the plurality of the first electrodes, forming the plurality of the second electrodes, and forming the plurality of the marks, singulating the semiconductor wafer into individual semiconductor laser elements each including at least one of the marks,