Enhancing energy density and efficiency in laser processing hinges on precise beam focusing, yet this often causes severe heat absorption and focus shifts in optical lenses. Traditional cooling methods increase cost and complexity, severely limiting versatility. Here, monolithic silicon carbide (SiC) metalens is introduced, which shows unparalleled thermal stability, integrated with a high‐power laser. This metalens achieves diffraction‐limited focusing with a numerical aperture (NA) of 0.5 and a focal length of 1 cm. Under a 1030 nm pulsed laser at 15 W for 1 h, it shows a minimal temperature rise of 3.2 °C and a tiny focal shift of 14 µm (0.1% relative), only 6% of the shift in conventional lenses. When used to cut a 4H‐SiC substrate with the same laser, the metalens exhibit only an 11.4% change in cutting depth after 1 h of operation, correlating with the focal shift results. The results unveil a groundbreaking class of compact SiC photonics devices nearly impervious to heat absorption, representing a monumental leap for high‐power laser systems and opening new horizons for their applications and efficiency.

中文翻译：

---

4H-SiC 超透镜：减轻高功率激光照射中的热漂移效应


提高激光加工中的能量密度和效率取决于精确的光束聚焦，但这通常会导致光学透镜出现严重的热吸收和焦点偏移。传统的冷却方法增加了成本和复杂性，严重限制了多功能性。这里介绍了单片碳化硅 （SiC） 超透镜，它与高功率激光器集成，显示出无与伦比的热稳定性。该超透镜可实现数值孔径 （NA） 为 0.5 且焦距为 1 cm 的折射极限聚焦。在 15 W 的 1030 nm 脉冲激光下持续 1 小时，它显示出 3.2 °C 的最小温升和 14 μm 的微小焦距偏移（相对 0.1%），仅为传统镜头偏移的 6%。当用于使用相同的激光器切割 4H-SiC 衬底时，超透镜在运行 1 小时后切割深度仅发生 11.4% 的变化，这与焦距偏移结果相关。结果揭示了一类几乎不受热吸收影响的开创性紧凑型 SiC 光子器件，代表了高功率激光系统的巨大飞跃，并为其应用和效率开辟了新的视野。