Influence of NaYF4 Inert and Active Layer on Upconversion Luminescence.

NaYF4:Yb,Er@NaYF4 core-shell nanostructures were prepared to investigate their influence on upconversion (UC) luminescence. Tests revealed green radiation (4S3/2→4I15/2) and red radiation (4F9/2→4I15/2) first increased and then gradually decreased as Yb concentration increased in the NaYF4 shell. The strongest fluorescent radiation occurred at an Yb concentration of 5%. To investigate the complicated variation of luminescence, we designed a set of experiments to study the impact of Yb ion concentration on luminescence intensity, and we analyzed the corresponding enhancement mechanism. It is probable that the energy transfers between both Yb and Er ions and Yb and Yb ions are involved in the UC processes. The enhancement of hybrid nanostructures has huge potential in biological detection and solar cells.

Optical planar and ridge waveguides formed in Er3+-doped germanate glass by ion implantation and precise diamond blade dicing.

In this work, we report on the preparation and characterization of the planar and ridge optical waveguides in the Er3+-doped germanate glass by combining hydrogen ion implantation and precise diamond blade dicing. The nuclear energy loss and the implantation depth were calculated by the SRIM 2013 software. The refractive index profile was obtained by the reflectivity calculation method. The dark-mode spectrum and the near-field intensity distribution were measured by the prism coupling system and end-face coupling technique, respectively. This work has important reference significance for the development of Er3+-doped germanate glass active devices in the optical communication field.

An Ultrashort Wavelength Multi/Demultiplexer via Rectangular Liquid-Infiltrated Dual-Core Polymer Optical Fiber.

We propose a rectangular liquid-infiltrated dual-core polymer optical fiber (POF) for short-range communication systems by the beam propagation method (BPM). The POF multi/demultiplexer (MUX/DEMUX) at the wavelengths of 0.52/0.65-µm, 0.57/0.65-µm, and 0.52/0.57-µm are devised. The simulation results demonstrate that the ultrashort length of three ultrashort POF couplers are 183.6 µm, 288 µm, and 799.5 µm. Compared with the conventional optical fiber couplers, these results could have significant applications in the miniaturization of optical devices for visible light communication.