Semiconductor laser device including columns of semiconductor lasers with non-central light emitting regions

A method of fabricating a semiconductor laser device including:

• preparing a unit semiconductor laser structure having front and rear surfaces and including a plurality of unit semiconductor lasers;
• forming a front surface electrode on the front surface of the unit semiconductor laser structure and forming a rear surface electrode on the rear surface of the unit semiconductor laser structure;
• cutting the unit semiconductor laser structure to form facets of each unit semiconductor laser and to form a semiconductor laser bar having front and back facets and in which the unit semiconductor lasers are arranged in an array, serially in contact at side surfaces, an active layer of each unit semiconductor laser being located in the center of each facet of each unit semiconductor laser with respect to the side surfaces of the unit semiconductor laser;
• depositing a low-reflectance film on the front facet of the semiconductor laser bar and depositing a high-reflectance film on the back facet of the semiconductor laser bar;
• cutting the semiconductor laser bar into the plurality of unit semiconductor lasers;
• laminating in a column on a submount at least two of the unit semiconductor lasers, including bonding the unit semiconductor lasers to each other so that the facets on which the low-reflectance film is deposited are in the same plane;
• and
• cutting the laminated unit semiconductor lasers at a plane passing through the center of the column of unit semiconductor lasers and parallel to the side surfaces, thereby forming a semiconductor laser device comprising a plurality of divided unit semiconductor lasers emitting light in the same direction and laminated in two columns.

A method of fabricating a semiconductor laser device including:

• preparing first and second unit semiconductor laser structures, each structure including a plurality of unit semiconductor lasers, having front and rear surfaces, and having interfaces between unit semiconductor lasers;
• forming front surface electrodes on the front surfaces of the unit semiconductor laser structures and forming rear surface electrodes on the rear surfaces of the unit semiconductor laser structures, an active layer of each unit semiconductor laser being located closer to the front surface electrode than to the rear surface electrode and the conductivity types of semiconductor layers of the first and second unit semiconductor laser structures between the front and rear surface electrodes, except the active layers, being opposite to each other;
• cutting the first and second unit semiconductor laser structures to form facets of each unit semiconductor laser and to thereby form first and second opposing semiconductor laser bars having front and back facets, respectively, and in which the unit semiconductor lasers are serially arranged in an array with adjacent pairs of unit semiconductor lasers in contact at respective interfaces, each adjacent pair of the unit semiconductor lasers having active layers located closer to the interface between the adjacent pair of unit semiconductor lasers than to other interfaces of the respective semiconductor laser bars;
• depositing a low-reflectance film on the front facets of the opposing semiconductor laser bars and depositing a high-reflectance film on the back facets of the opposing semiconductor laser bars;
• cutting the first and second opposing semiconductor laser bars at interfaces remote from the active layers of the adjacent pairs of the unit semiconductor lasers to form first and second opposing semiconductor laser chips, respectively, each chip comprising an adjacent pair of the unit semiconductor lasers;
• and
• bonding the first semiconductor laser chip that is cut from the first semiconductor laser bar at the rear surface electrode to a submount and bonding the second semiconductor laser chip that is cut from the second semiconductor laser bar at the front surface electrode directly to the front surface electrode of the first semiconductor laser chip so that the facets of the first and second laser chips on which the low-reflectance film is deposited are in the same plane.