Remtec Inc. has added new capabilities for laser diode, LED and photodiode submounts and substrates, giving designers a wider variety of packaging options with ceramic submounts (alumina, beryllia, aluminum nitride), metal heat sinks and enhanced plated gold tin metallization. The improvements, along with the advantages of plated copper on thick-film technology, enable many more options to gain higher performance from smaller, more cost-effective packages for electro-optical applications. The laser and photodiode submounts offer 25- to 75-µm-thick copper metallization with "zero pullback metallization" from a burr-free ceramic edge, enhancing the performance of edge-emitting diodes. An additional benefit is gold tin plating on ceramic submounts, used for both edge-emitting and vertical external-cavity surface-emitting laser diodes. This option also can be applied to copper tungsten submounts and laser bars.