Tm³⁺-doped LuScO₃ mixed sesquioxide ceramics were successfully fabricated by using a solid-state reactive sintering method. The absorption and emission spectra were measured at room temperature. Continuous-wave (CW) and passively Q-switched laser operation of Tm³⁺:LuScO₃ ceramic were investigated for the first time to our knowledge. A CW output power of 211 mW with slope efficiency of about 8.2% was obtained. With single-walled carbon nanotube (SWCNT) as saturable absorber, a maximum average output power of 32 mW was achieved. The shortest pulse width was 0.59 μs at pulse repetition rate of 34.72 kHz.

In this paper, we report the fabrication of high-quality 5 at. % Er³⁺ ions doped SrF₂ transparent ceramics, the potential candidate materials for a mid-infrared laser-gain medium by hot-pressing at 700 °C for 40 h using a chemically-derived powder. The phase structure, densification, and microstructure evolution of the Er:SrF₂ ceramics were systematically investigated. In addition, the grain growth kinetic mechanism of Er:SrF₂ was clarified. The results showed lattice diffusion to be the grain growth mechanism in the Er:SrF₂ transparent ceramic of which highest in-line transmittance reached 92% at 2000 nm, i.e., very close to the theoretical transmittance value of SrF₂ single crystal. Furthermore, the emission spectra showed that the strongest emission band was located at 2735 nm. This means that it is possible to achieve a laser output of approximately 2.7 μm in the 5 at. % Er³⁺ ions doped SrF₂ transparent ceramics.

Multiwall boron nitride (BN) nanotubes were synthesized by a novel physical vapor deposition (PVD) method, in which the BN nanotubes grow on a compact substrate composed of AlN, γ-Al₂O₃, Y₂O₃, and carbon powders. The obtained BN nanotubes assemble in an orderly manner with a typical length of over one millimeter and a diameter of one-hundred nanometers. The hollow multiwall tubes have a spherical tip, which is presumed to be a liquid drop at the synthesis temperature, indicating the vapor–liquid–solid (VLS) growth mechanism.