Controlling luminescent silicon nanoparticle emission produced by nanosecond pulsed laser ablation: role of interface defect states and crystallinity phase

In this study, we provide a systematic study on the origin of green and blue emission from luminescent silicon nanoparticles (Si-NPs) synthesized in water using a nanosecond pulsed laser ablation methodology.

Large bandwidth mode order converter by differential waveguides

In this article, we propose a large bandwidth mode-order converter design by dielectric waveguides with equal lengths but different cross-sectional areas. The efficient conversion between even and odd modes is verified by inducing required phase difference between the equal length waveguides of different widths. Y-junctions are composed of both tapered mode splitter and combiner to connect mono-mode waveguide to multi-mode waveguide. The converted mode profiles at the output port show that the device operates successfully at designed wavelengths with wide bandwidth. This study provides a novel technique to implement compact mode order converters and direction selective/sensitive photonic structures.

Thin film MoS₂ nanocrystal based ultraviolet photodetector

We report on the development of UV range photodetector based on molybdenum disulfide nanocrystals (MoS₂-NCs). The inorganic MoS₂-NCs are produced by pulsed laser ablation technique in deionized water and the colloidal MoS₂-NCs are characterized by transmission electron microscopy, Raman spectroscopy, X-ray diffraction and UV/VIS absorption measurements. The photoresponse studies indicate that the fabricated MoS₂-NCs photodetector (MoS₂-NCs PD) operates well within 300-400 nm UV range, with diminishing response at visible wavelengths, due to the MoS₂-NCs absorption characteristics. The structural and the optical properties of laser generated MoS₂-NCs suggest promising applications in the field of photonics and optoelectronics.