Surface Characteristics of Polished YAG Laser Crystal

Abstract

Compared with ordinary optical glass, it is much more difficult to achieve high‐precision and ultra‐smooth surface processing on laser crystal materials. In order to improve the processing technology of large‐size Y3Al5O12 (YAG) laser crystal components, the surface characteristics of polished YAG crystal are studied. First, the surface mechanical properties of polished YAG crystal are investigated by nanoindentation technology, and the machinability of the crystal is basically evaluated. Then, the characteristics of surface flatness, defects, and surface roughness related to processing requirements of crystal components are further studied. The experimental results show that the high flatness, low defect density, and super smoothness of the surface of YAG crystal material can be obtained by optimizing the polishing process, that is, using a three‐step polishing method combining Al2O3 abrasive and the composite tin polishing plate.

Single crystal growth and effect of cleavage micro-striations on the crystallinity and optical properties of mercurous halide single crystals

“…Therefore, alumina was chosen as the main component of the polishing liquid. [37][38][39] Firstly, 7000 grit silicon carbide sandpaper was used to remove the cutting marks on the crystal surface, and then 0.3 and 0.05 μm Al 2 O 3 powder and alcohol were used to prepare polishing solutions, respectively. As shown in Fig.…”

Insight into Polishing Slurry and Material Removal Mechanism of Photoassisted Chemical Mechanical Polishing of YAG Crystals

“…After polishing, the surface roughness was 0.08 nm Sa, but the measurement range was limited to 10 nm × 10 nm. Xie et al 17 employed Al 2 O 3 abrasives with three particle sizes to polish YAG crystals, and the surface roughness was 0.49 nm Ra. However, this approach involved multiple time-consuming steps.…”

Mechanical Properties and Nanoindentation Size Effects of YAG Crystals with Different Crystal Faces

“…YAG crystal, one of the most often used laser crystal materials in solid state lasers, has a high melting point, great mechanical qualities, outstanding thermal conductivity, and strong light resistance. [1][2][3][4][5][6][7] In order to ensure the performance of the laser, YAG crystal elements require extremely high optical processing DOI: 10.1002/crat.202300091 accuracy. [5] However, YAG crystal is a typical hard and brittle material, which is insoluble in any acid or alkali at room temperature, making it difficult to process.…”

“…[1][2][3][4][5][6][7] In order to ensure the performance of the laser, YAG crystal elements require extremely high optical processing DOI: 10.1002/crat.202300091 accuracy. [5] However, YAG crystal is a typical hard and brittle material, which is insoluble in any acid or alkali at room temperature, making it difficult to process. [7] The main processing methods for YAG crystal are still lapping and polishing, and the process relies on the mechanical action of abrasives to complete the material removal, so the processing efficiency is low, and the processed surface is prone to damage such as scratches, chipping, and microcracks.…”