Transparent ceramics for high-power infrared lasers operating above 2 μm

Solid-state lasers are a key part of advanced devices and great efforts has devoted to improving their performance, including the research of novel materials as a powerful alternative to conventional glass or single-crystals. We demonstrated a versatile sol-gel approach to nanocrystalline (Ho0.03La0.97)(2)Zr2O7 thin films. We proved Ho3+ ions regularly substituted La3+ ions in the host matrix. The residual -OH groups were presented in the samples bonded on La3+ ions. The highest phonon energy was 653 cm(-1) allowing the luminescence up to 3.06 mu m. The film of the thickness of 380 nm showed a refractive index of 2.28 at a wavelength of 632 nm. The sample showed luminescence spectra characteristic for Ho3+ ions. The emission maximum was observed for the electronic transition I-5(7) -> I-5(8) at 2.1 mu m. The luminescence intensity of the electronic transition I-5(6) -> I-5(7) at 2.9 mu m reached 7% of the maxima. The luminescence decay time recorded at 2.1 mu m and 2.9 mu m was 6.814 ms and 0.565 ms, respectively. High thermal and chemical stability of proposed materials, together with advanced processing methods open new horizons in technology of the mid-infrared active waveguides and fibers with improved lasing efficiency and stability.