Some metallization systems consisting of barrier metals and Au-Sn (multiple alternating layers) were studied as a bonding schemes of InP-based laser diodes to the first time used, CVD-diamond submounts. The first system to be studied, which was traditionally used in various other applications was Ti(100nm)/Pt(200nm)/Au(500nm)/Au-Sn(2.5 μm). This structure provided a molten Au-Sn layer of eutectic composition (80:20 wt%) on top of the Ti/Pt metals for about 6 sec, while heated at temperatures of 300 to 350°C, and allowed for efficient bonding of the device to the submount. Longer heating durations, however, led to reaction between Pt and Sn to consume significant amounts of Sn from the solder, thus elevating its melting temperature and resolidifying the solder. With optimum bonding conditions, a high quality bond of the InP-based laser diode to the CVD-diamond submount was observed, and a superior electrical performance of the diode was measured compared to diodes that were bonded with the standard In/BeO configurations. In order to maintain the superior performance of the InP laser diode bonded assembly but improve the thermodynamic stability of the metallurgical system and thus extending the bonding processing window, various metals such as W and Cr were studied as a replacement for the Ti/Pt barrier metals in between the CVD-diamond submount and the Au-Sn solder. While applying the W layer, a thin Ti(10nm) layer was introduced in between it and the Au-Sn to improve the solder wettability. The W layer was found to remain intact after heating at 350°C for durations as long as 5 min, and thus, due to the inert nature of the Au-Sn/W interface, the Au-Sn ratio was kept uniform at the eutectic liquid composition through a long heating duration (up to 5 min). Minimum reaction was observed, as well, at the Au-Sn/Cr interface, while executing a Ti(100nm)/Cr(200nm)/Au-Sn(1.5 μm) system, and thus allowed for an excellent bonding of the InP laser diodes to the CVD-diamond submounts.