Main housing for optical sub-assembly for transceivers

A main housing for optical sub-assembly for transceivers includes a cylindrical member and a bypass member. The cylindrical member has a first end for accommodating an optical transmission unit and a second end for accommodating an optical fiber connector. A tubular member forming groove is formed on an outer circumference of the cylindrical member. A sleeve forming reference hole is formed on a tubular wall of the cylindrical member in communication with the tubular member forming groove. The bypass member has a connection tube positioned in the tubular member forming groove, a filter holder positioned in the cylindrical member and connected with the connection tube for connecting a filter on the filter holder, and a sleeve for accommodating an optical receiving unit. The sleeve outward extends along the sleeve forming reference hole and is connected with the filter holder.