Method of manufacturing a cap for accommodating a laser diode, a cap, and a light source device

A method of manufacturing a cap having a recess configured to accommodate a laser diode, the method comprising:

• providing a first plate for forming a front wall that defines a front side of the recess, at least a portion of the front wall being formed of a material that transmits laser light to be emitted from the laser diode;
• providing a second plate for forming a rear wall that defines a rear side of the recess, the rear wall being opposed to the front wall;
• providing a third plate for forming a main body that defines an upper side and lateral sides of the recess and is connected to the front wall and the rear wall, wherein:
• the third plate has a plurality of through-holes that are arranged in a two-dimensional array along a first direction and along a second direction,
• the first direction extending in a plane that is orthogonal to a thickness direction of the third plate, and
• the second direction extending in the plane and orthogonal to the first direction;
• bonding the first plate and the third plate together, and bonding the second plate and the third plate together, to produce a stacked body in which the third plate is interposed between the first plate and the second plate;
• and
• singulating the stacked body, which comprises cutting the stacked body along the first direction and along the second direction to produce a plurality of caps from the stacked body, wherein:
• when the stacked body is cut along the first direction, a first incision is made along inner wall surfaces defining through-holes adjacent along the first direction, the inner wall surfaces extending along the first direction and the thickness direction, and
• when the stacked body is cut along the second direction, a second incision is made at a position spaced from through-holes adjacent along the second direction.