Transparent Er(3+)-Doped Y(2)O(3) Ceramics with Long Optical Coherence Lifetime

[Image: see text] Er(3+)-doped Y(2)O(3) nanoparticles (NPs) are used to synthesize transparent ceramics by hot isostatic pressing. Two sizes of NPs are studied, and 40 nm NPs show better performance than 200 nm NPs in transparent ceramics syntheses. The axial optical transmission through millimeter thickness of the prepared ceramics is about 80% in the wavelength range of 1000–2000 nm. For a sample with 11.5 ppm Er(3+), the inhomogeneous broadening of the (4)I(15/2) to (4)I(13/2) transition for the C(2) site is as low as 0.42 GHz (full width at half-maximum), and the homogeneous line width is 11.2 kHz at a temperature of 2.5 K and in a 0.65 T magnetic field. This indicates that a majority of Er(3+) ions are sitting in sites with very low structural disorder.