Illumination optical unit for endoscope and method of manufacturing the same

A method of manufacturing an illumination optical unit for an endoscope including an optical fiber that guides a laser beam supplied from a laser beam source to a distal end of the optical fiber and emits the guided laser beam from the distal end;

• a fluorescent body that is excited by the laser beam emitted from the optical fiber to emit florescent light and that forms white light consisting of the fluorescent light and the laser beam;
• a holding member that holds the fluorescent body, has a fluorescent body holding portion opened on a distal end side, and a through hole that is continuous from a proximal end of the fluorescent body holding portion and allows the optical fiber to be inserted therethrough, and is formed in a substantially cylindrical shape;
• a sleeve member that has an inner peripheral face fitted to an outer peripheral face of the holding member and has a distal end and a proximal end opened;
• and a protective cover that is held by the sleeve member, covers the distal end side of the fluorescent body, and transmits the fluorescent light and the laser beam,
• the method comprising:
• bonding the sleeve member and the protective cover to seal the distal end side of the fluorescent body;
• inserting the holding member holding the fluorescent body and the optical fiber into the inside of the sleeve member from a proximal end side of the sleeve member with the distal end being sealed by the protective cover, to bring the fluorescent body into close contact with the protective cover;
• and
• bonding the holding member and the sleeve member together to seal the proximal end side of the fluorescent body, in a state where the fluorescent body is brought into close contact with the protective cover, and the optical fiber is arranged on the proximal end side of the fluorescent body.