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

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

• 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;
• a rear wall that defines a rear side of the recess, the rear wall being opposed to the front wall;
• a main body that that defines an upper side and lateral sides of the recess defining a cavity and is connected to the front wall and the rear wall;
• and
• an antireflection coating provided on a surface of the front wall;
• wherein:
• lower end surfaces, respectively, of the front wall, the rear wall, and the main body define a bonding surface of the cap;
• and
• in a plan view as seen from a normal direction of the front wall, a perimeter of the antireflection coating is spaced from the lower end surface of the front wall.