Single-crystal lutetium oxide (Lu2O3), owing to its high thermodynamic stability and wide amplification bandwidth, represents a promising gain medium for high-power solid-state laser applications. Despite its extensively recognized advantages, its high hardness and chemical stability significantly hinder effective processing strategies for achieving surfaces with low damage and excellent smoothness. Conventional chemical mechanical polishing is widely employed to eliminate subsurface damage (SSD) generated during ultra-precision grinding and to achieve high-quality finishes; however, its low processing efficiency remains a critical limitation. Here, inductively coupled plasma-assisted modification was introduced for the first time in single-crystal Lu2O3 processing, combined with low-pressure polishing to eliminate the softened modification layer, yielding an ultrasmooth surface with a roughness (Sa) of 0.61 nm. Overall, this integrated approach effectively balances high processing efficiency with minimal processing-induced damage, offering a novel approach to rapidly eliminate SSD layers in hard, brittle materials after ultra-precision grinding.
Liu et al. (Tue,) studied this question.