A system for retaining an optical element with a card assembly and heat sink is provided. The retaining system includes an optical element fastener and a retainer member. The optical element fastener is configured to hold the optical element to the heat sink. The retaining member is configured to hold the card assembly to the heat sink, and also serves to make the optical element fastener captive. In one embodiment, the retaining member includes a ridge for holding the card assembly to the heat sink. The top end of the retainer member may also include one or more recessed slots for tool engagement to facilitate fastening of the retainer member. In one embodiment, the retaining member is threaded at the bottom end to fasten the retaining member to the heat sink. Also, in one embodiment the retaining member includes an axial opening used to access the optical element fastener.