Tongji University Develops 3D-Printed Copper Mirror to Enhance Laser Mirror Durability

SHANNON, CLARE, IRELAND, October 13, 2026 /CourierPR/ -- Tongji University researchers have developed a 3D-printed copper mirror that significantly enhances the durability of optical components in high-power laser systems, particularly in extreme ultraviolet (EUV) lithography. This breakthrough could revolutionize the semiconductor industry by addressing a critical challenge: preventing mirrors from overheating and degrading under intense laser exposure.

The innovative mirror integrates a 3D-printed copper water-cooling structure, copper surface modification, and a high-reflection coating. The fabrication process involves several steps: first, a 3D-printed copper water-cooling structure is created, followed by copper surface modification and secondary ultra-precision turning. Finally, a multilayer reflective coating, incorporating gold, germanium, and zinc sulfide, is applied to achieve over 99.5% reflectance at a wavelength of 10.6 micrometres.

Experimental results demonstrate that the water-cooling system significantly improves the mirror's performance. Without cooling, the mirror's surface temperature reached 84.2°C under laser irradiation. With water cooling, the temperature dropped to 45°C, a reduction of approximately 53%. This substantial decrease in temperature also translates to a 60% increase in the mirror's laser-induced damage threshold, from 8,488 to 13,581 W/cm². Additionally, water cooling reduced peak-to-valley thermal deformation by approximately 75%, helping to preserve the mirror's optical shape under intense heating.

The study, published in Opto-Electronic Advances, highlights the potential of additive manufacturing and integrated liquid cooling for developing more resilient optical components in high-power laser systems and other precision industrial equipment. The journal, with an impact factor of 22.4 (Journal Citation Reports 2024), has expanded its Editorial Board to 41 members from 17 countries, ensuring a diverse and robust peer review process.

The research team's findings could have significant implications for the semiconductor industry, where EUV lithography is crucial for manufacturing cutting-edge microchips. By overcoming the challenge of laser-induced damage, the new mirror could support the development of more reliable and thermally stable laser mirrors, potentially enabling the next generation of advanced semiconductor manufacturing technologies.