Towards Efficient Electrically-Driven Deep UVC Lasing: Challenges and Opportunities.

The major issues confronting the performance of deep-UV (DUV) laser diodes (LDs) are reviewed along with the different approaches aimed at performance improvement. The impact of threading dislocations on the laser threshold current, limitations on heavy n- and p-doping in Al-rich AlGaN alloys, unavoidable electron leakage into the p-layers of (0001) LD structures, implementation of tunnel junctions, and non-uniform hole injection into multiple quantum wells in the active region are discussed. Special attention is paid to the current status of n- and p-type doping and threading dislocation density reduction, both being the factors largely determining the performance of DUV-LDs.

Tunable near-infrared Gires-Tournois resonators based on vanadium dioxide on gold film.

Vanadium dioxide (VO) has been proposed as a phase-change material in tunable photonic and optoelectronic devices. In such devices, a thin layer of VO is typically deposited on metallic or insulating surfaces. In this Letter, we report the reflectance spectra of a subwavelength structure consisting of a thin layer of VO deposited on a gold film in the near-infrared spectral range, particularly near the wavelength of 1550 nm, which is significant for telecommunication applications.

The anodization voltage influence on the properties of TiO2 nanotubes grown by electrochemical oxidation.

A systematic study of titanium dioxide (TiO2) nanotubes (NTs) grown by electrochemical anodization in NH4F + glycerol electrolyte has been carried out in a broad range of anodization voltage of 5-350 V and acid concentration of 0.1-0.7 wt%.