Low thermal stress and high-strength interface in brazing welding Nd:YAG-based advanced laser components

Area of Science:

• Materials Science
• Optics and Photonics
• Mechanical Engineering

Background:

• Packaging advanced Nd:YAG laser components using Cu/Nd:YAG joints faces challenges due to thermal expansion mismatch and poor metallurgical compatibility.
• High thermal stress and void defects in these joints degrade laser beam quality and structural integrity.

Purpose of the Study:

• To develop an efficient packaging solution for Nd:YAG-based laser components with reduced thermal stress and improved structural integrity.
• To fabricate practical Cu/Nd:YAG/Cu laser components suitable for space-grade applications.

Main Methods:

• Utilized low-temperature braze welding at 190 °C.
• Designed a Ti-Pt-Au film as a transition layer.
• Employed a vacuum-deposited indium film as the welding layer.

Main Results:

• Achieved reduced thermal stress and sound joints in Cu/Nd:YAG components.
• Successfully fabricated sandwiched Cu/Nd:YAG/Cu laser components for space applications.
• Demonstrated that the components satisfy beam morphology and thermal stress requirements under extreme satellite operating conditions.

Conclusions:

• The developed braze welding approach provides an efficient packaging solution for Nd:YAG laser components.
• This method enriches the theoretical understanding of achieving low thermal stress and high-strength interfaces in dissimilar ceramic/metal joints.
• The findings are crucial for enhancing the reliability and lifetime of laser systems in demanding environments like space.