3D-Printed Copper Mirror Cuts Laser Heat Damage

Researchers at Tongji University have built a 3D-printed copper mirror with internal water cooling that improved resistance to laser-induced damage by about 60%. The design could help semiconductor makers protect optics used in EUV lithography and other high-power laser systems.

Why it matters: - Semiconductor manufacturers need optics that can survive extreme laser heat without warping or failing. - The new mirror design points to a practical way to cool precision components inside advanced chipmaking tools. - Stronger laser mirrors could improve reliability in EUV lithography and similar high-power systems.

What happened: - Researchers at Tongji University in China developed a 3D-printed copper mirror with internal water-cooling channels. - The work appeared in Opto-Electronic Advances. - The mirror was designed for high-power CO₂ laser reflectors used in semiconductor manufacturing contexts.

The details: - The team used laser powder bed fusion to fabricate the copper mirror. - The mirror included a copper surface-modification layer and a multilayer reflective coating made with gold, germanium and zinc sulfide. - The coating achieved more than 99.5% reflectance at 10.6 micrometres. - Under laser irradiation, surface temperature fell from 84.2°C without cooling to 45°C with water cooling. - That temperature drop cut measured heat buildup by about 53%. - The laser-induced damage threshold rose from 8,488 to 13,581 W/cm². - That was a 60% increase in damage resistance. - Computer simulations showed peak-to-valley thermal deformation dropped by about 75% with water cooling. - Copper surface modification outperformed nickel in protecting the mirror.

Between the lines: - The results suggest that thermal management can be built directly into optical components rather than added around them. - Additive manufacturing makes it possible to create internal cooling channels that would be difficult to produce with traditional methods. - The copper advantage underscores how material choice can shape heat tolerance in high-power laser optics.

What's next: - Further development is still needed before industrial deployment. - The approach could be extended to other precision optical components in high-power laser systems and industrial equipment. - The findings may help support next-generation semiconductor manufacturing tools that depend on more stable mirrors.

The bottom line: - A 3D-printed, water-cooled copper mirror materially improved laser heat resistance and optical stability, offering a promising path for tougher chipmaking optics. - More information is available in the journal announcement. - The study is titled “3D-printed copper water cooling system assisted fabrication of 10.6-μm high-power CO2 laser resistance reflectors.”