An optical module includes a housing, a heat sink apparatus arranged in and thermally connected to the housing, and a printed circuit board partially arranged on the heat sink apparatus. The optical module further includes an optoelectronic chip arranged on the heat sink apparatus. The printed circuit board has a first surface, a second surface opposite to the first surface, and an opening that extends from the first surface to the second surface. The heat sink apparatus is connected to the second surface. The opening is located near a center of the printed circuit board. The optoelectronic chip is arranged in the opening.