Transfer molding type manufacturing method of pigtail-type optical module

A method for manufacturing a pigtail-type optical module comprising an optical fiber, an optical element and an electronic circuit, the optical fiber and the optical element being coupled by a light beam having a central axis being a predetermined angle with a central axis of a ferrule, the method comprising the steps of:

• transfer molding an assembly comprising the optical element, a holder portion capable of receiving a ferrule, and the electric circuit to produce a single unit assembly;
• said inner diameter of the holder portion being larger than an outer diameter of the ferrule;
• grinding an end face of the optical fiber so that an end face of the optical fiber is inclined from a plane perpendicular to an optical axis of the end portion of the optical fiber;
• attaching the optical fiber end portion to the ferrule so that the central axis of the ferrule and the optical fiber are substantially shared;
• inserting the ferrule attached to the optical fiber end portion into the holder portion of the molded single unit assembly;
• adjusting an optical coupling efficiency between the optical element and the optical fiber by moving the ferrule in and opposite to its insertion direction, by moving the ferrule in a direction perpendicular to the insertion direction of the ferrule, and by rotating the ferrule axially about its insertion direction.