Fabrication of Nd:YAG crystal slab using composite lap

The present work investigates the fabrication process of precision Nd:YAG crystal slab which is extensively used in high-power slab lasers. Properties of the crystal and problems during fabrication were analyzed. A novel process based on the composite lap was proposed. Fabrication of a 100 mm30 mm3 mm sample revealed the validation of this process. Experiment results indicated that the composite lap was superior to conventional lap material for controlling edge collapsing in polishing process. Defect-free surface could be obtained using optimal size and size distribution of Al2O3 slurry. The surface figure of slab TIRs surface was 0.217, while that of the end surface was 0.1. The surface roughness approached 0.55 nm RMS. The precision of the intersection angle was 2.