Abstract: An integrated optical package comprises an integrated optical device supported on a carrier with a gelatinous material therebetween to assist in heat conduction. The carrier can include a thermal regulating device such as a heat sink or heater for regulating the temperature of the integrated optical device via the gelatinous material. The gelatinous material can include a metallic second phase suspended in the gelatinous material, to improve its thermal conductivity. The maximum dimension of the particles is ideally smaller than the gap between the integrated optical device and the carrier in which the gelatinous material is located, such as in the 5 to 95 percent range of the dimension of the gap. The particles of the metallic second phase can be elongate, in which case they can be aligned with each other such as in a direction extending from the integrated optical device towards the carrier. Alternatively, they can be substantially spherical.