When multicasting in optical networks is implemented within the switching control plane, it combines the efficiency of multicast tree along with high speed and low delay of optical communications. Multicast nodes must be equipped with light splitters. Light splitters are expensive equipment. Therefore, a limited number of optical nodes will have this splitting capability. A good placement of optical splitters can increase the efficiency of the multicast signaling and routing techniques on one hand, and reduce the number of those splitters on the other hand. This leads to faster multicast trees setting up, lower data transmission delays, and less traffic on the network links; thus saving of optical links capacity for other multicast and unicast transmissions. In order to achieve efficient multicasting in optical network, we propose to take into account network characteristics (link capacity and node degree) when placing the optical splitters. The benefits of the smart placement of light splitters will be clearly shown in heterogeneous optical networks, where multicast traffic is not uniformly distributed over the network, and optical links connecting different nodes in the network have different characteristics.