Abstract: A laser diode is mounted on a plate that fits closely within a mortise in a thermally conductive insert. The insert, in turn, fits closely within a thermally conductive sleeve. The plate has six sides and the laser diode is attached to one of the sides. Heat is conducted away from the remaining five sides of the plate. The insert includes a conic section that fits within a conic section in the sleeve to provide good thermal contact between the insert and the sleeve. The sleeve includes a plurality of holes and contains a fan for circulating air through the sleeve, thereby removing heat from the sleeve. The sleeve includes a cylindrical portion for being held in a hand.