Characteristics of ultraviolet amplified spontaneous emission from zinc oxide nanowires

Abstract Hexagonal zinc oxide nanowires were fabricated on (1 0 0) silicon substrate by vapor-phase transport method. The scanning electron microscopy (SEM) image shows that the diameter of the nanowires are about 50 nm and the length is about 10 μm. Each nanowire has uniform diameter along length direction. The X-ray diffraction (XRD) analysis indicates that the nanowires mainly grew along [0 0 0 1] direction and had a good crystal quality. The ultraviolet amplified spontaneous emission (ASE) was observed when the nanowires were excited by a frequency-tripled Nd:YAG laser with 355 nm wavelength. The variation of intensity and linewidth of the ASE with pump intensity was discussed based on a three-level model.