AuSn thin film is a critical technology to enable optoelectronic device to ensure durability, anti-oxidation ability and reliability compared with Indium, SnPb, SnBi etc.. The application of AuSn is primarily in optoelectronic chip bonding, but also in housing assembling, lens assembling, etc.. AuSn can be pre-deposited on various substrate materials, such as the commonly used materials AlN, CuW, SiC, glass, CVD Diamond, Copper Diamond (CuD) for different applications. Focuslight is a technology leader in AuSn thin film deposition and AuSn bonding process with more than 10 years experience. Focuslight becomes a vendor for AuSn pre-deposited substrates with various substrate materials and AuSn deposition technical service. The design, key processes and application data of high power laser diode device will be presented.