An insulation device arranged to be fixed on an electrical board of an optical wireless communication equipment, and including an enclosure having a height at least equal to a height of an optical assembly including an optical concentrator, the enclosure including in its thickness an opaque material, the insulation device including at least one housing, the insulation device being arranged such that, when the insulation device and the optical assembly are mounted on the electrical board, the enclosure surrounds the receiving surface so as to insulate the optical assembly from unwanted optical signals, and the optical concentrator is positioned in the housing so that the housing assists in holding the optical concentrator in position in the optical wireless communication equipment.