Optical semiconductor package and its fabrication process, in which: a rear face of a first semiconductor component (3) such as a microprocessor is supported by a front face of an electrical connection support plate (1); a rear face of a second semiconductor component (11) is fixed to a front face of the said first component (3) and a front face of this second component has an optical sensor (13); first electrical connection means (6) connect the said first component to the front face of the said support plate; second electrical connection means (14) connect the said second component to the front face of the said support plate; means (17) ensure encapsulation of the said components stacked on the said support plate and of the said electrical connection means, the said encapsulation means being made from a transparent material which is opposite the said optical sensor; and external electrical connection means (24) are located on an exposed part of the said support plate.