Direct bonding diamond to zinc selenide

We report direct bonding of 5mm dia x 500μm thick polycrystalline CVD-grown diamond to 25mm dia x 4mm ZnSe via a plasma-assisted technique. In addition, diamond to C-cut sapphire bonding is demonstrated via the same approach. Durability of the diamond/ZnSe bond is tested over a temperature range -40 to 150 oC and under various ramp rates, demonstrating strong adhesion over the majority of the bond up to a temperature of 80 oC. Optical transmission at a wavelength of 1μm shows near ideal transmission when compared to bare ZnSe. Heatspreading performance of the bonded composite is investigated using a pump-probe arrangement, demonstrating at least two-orders of magnitude reduction in the thermal-lens power compared to ZnSe alone.