Effect of hot pressing pressure on the microstructure and laser performance of Yb:CaF2 transparent ceramics

Year: 2025

Authors: Li X., Guo L.H., Hu C., Wu J.L., Toci G., Pirri A., Patrizi B., Vannini M., Liu Q., Li J.

Autors Affiliation: Chinese Acad Sci, Transparent Ceram Res Ctr, Shanghai Inst Ceram, Shanghai 201899, Peoples R China; Jiangsu Univ, Sch Mat Sci & Engn, 301 Xuefu Rd, Zhenjiang 212013, Peoples R China; Univ Chinese Acad Sci, Ctr Mat Sci & Optoelect Engn, Beijing 100049, Peoples R China; CNR INO, Ist Nazl Ott, Consiglio Nazl Ric, Via Madonna Piano 10C, I-50019 Sesto Fiorentino, FI, Italy; CNR IFAC, Consiglio Nazl Ric, Ist Fis Applicata Carrara, Via Madonna Piano 10C, I-50019 Sesto Fiorentino, FI, Italy.

Abstract: The 5 at.% Yb:CaF2 transparent ceramics were synthesized using a combination of hot pressing (HP) and hot isostatic pressing (HIP) from co-precipitated powders. The influence of varying HP pressures on the microstructure and laser performance of these ceramics was investigated. It was found that the optical quality of the CaF2 ceramics was significantly influenced by the HP pressure. Field emission scanning electron microscopy (FESEM) results indicated that HP pressure markedly affected the average grain size of the Yb:CaF2 ceramics. The sample that was hot pressed under 40 MPa and subsequently HIP post-treated at 600 degrees C for 3 h demonstrated the highest optical quality, achieving an in-line transmittance of 92.2 % at 1200 nm (2 mm thickness), with an average grain size of just 379 nm. Additionally, the ceramics processed under 20 MPa and then HIP post-treated at 600 degrees C showed superior laser performance, with a maximum output power of 1.25 W and a maximum slope efficiency of 13.5 %. This study offers valuable insights into the sintering mechanisms of fluoride-based ceramics and serves as a reference for enhancing the optical quality of Yb:CaF2 transparent ceramics.

Journal/Review: OPTICAL MATERIALS

Volume: 159      Pages from: 116605-1  to: 116605-9

More Information: This work was supported by the National Key R & D Program of China (Grant No. 2023YFB3812000) .
KeyWords: Yb:CaF2; Transparent ceramics; Microstructure; Laser performance
DOI: 10.1016/j.optmat.2024.116605