Nanowire photonics toward wide wavelength range and subwavelength confinement [Invited]

Semiconductor nanowires have attracted much attention for photonic applications, especially for lasers, because of their availability in a wide variety of materials and compositions, exceptionally small size, and rich functionality. So far, most nanowire laser studies have been done in rather short wavelength (lambda) ranges of less than 1 mu m. In addition, the diameter (d) of most nanowire lasers has been relatively large (d > lambda/n, n is the refractive index) because of the requirement for sufficient optical confinement. Recently, however, we are seeing new trends in nanowire research towards much longer wavelengths and much thinner nanowires for photonic applications. This article reviews the latest research activities in these directions, which shows that it is possible to fabricate excellent nanowire lasers operating at telecom wavelengths or even in the mid-infrared region and extremely thin subwavelength nanowires can be applied to make nanophotonic devices in a wide range of wavelengths. We believe that these research trends will have an impact on applications for functional energy-saving devices in future photonic integrated circuits. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement