Unique light-matter interaction at nanophotonic regime can be harnessed for designing efficient photonic and optoelectronic devices such as solar cells, lasers, and photodetectors. In this work, periodic photon nanowells are fabricated with a low-cost and scalable approach, followed by systematic investigations of their photon capturing properties combining experiments and simulations. Intriguingly, it is found that a proper periodicity greatly facilitates photon capturing process in the nanowells, primarily owing to optical diffraction. Meanwhile, the nanoengineered morphology renders the nanostructures with a broad-band efficient light absorption. The findings in this work can be utilized to implement a new type of nanostructure-based solar cells. Also, the methodology applied in this work can be generalized to rational design of other types of efficient photon-harvesting devices.

We report a partially directional microdisk semiconductor laser with subwavelength-scale boundary perturbations for asymmetric backscattering of counterpropagating whispering gallery modes. Unlike the previous approaches based on optical bistability, the directionality and chirality of the laser modes can be fine-tuned and partially controlled by adjusting the dimension, shape, and relative positions of Rayleigh scatterers on the microdisk perimeter. The controlled directionality is investigated using numerical simulations and experiments for wavelength-scale microdisk resonators with an azimuthal mode number of 5.

We discuss the rapid in situ hydrothermal synthesis of metal oxide materials based on the photothermal superheating of light‐absorbing metal layers for simple and facile on‐demand placement of semiconductor materials with micrometer‐scale lateral resolution. Localized heating from pulsed and focused laser illumination enables ultrafast growth of metal oxide materials with high spatiotemporal precision in aqueous precursor solution. Among many possible electronic and optoelectronic applications, the proposed method can be used for laser‐based in situ real‐time soldering of separated metal structures and electrodes with functionalized semiconductor materials. Resistive electrical interconnections of metal strip lines as well as sensitive UV detection using photohydrothermally grown metal oxide bumps are experimentally demonstrated.

Optofluidic manipulation mechanisms have been successfully applied to micro/nano-scale assembly and handling applications in biophysics, electronics, and photonics. Here, we extend the laser-based optofluidic microbubble manipulation technique to achieve hybrid integration of compound semiconductor microdisk lasers on the silicon photonic circuit platform. The microscale compound semiconductor block trapped on the microbubble surface can be precisely assembled on a desired position using photothermocapillary convective flows induced by focused laser beam illumination. Strong light absorption within the micro-scale compound semiconductor object allows real-time and on-demand microbubble generation. After the assembly process, we verify that electromagnetic radiation from the optically-pumped InGaAsP microdisk laser can be efficiently coupled to the single-mode silicon waveguide through vertical evanescent coupling. Our simple and accurate microbubble-based manipulation technique may provide a new pathway for realizing high precision fluidic assembly schemes for heterogeneously integrated photonic/electronic platforms as well as microelectromechanical systems.

We investigate experimentally and theoretically the highly direction-selective emission with small angular divergence in a metal-dielectric-metal structure with a subwavelength metal aperture layer. The thicknesses of the dielectric layer and top metal layer play important roles in controlling the emission direction and angular divergence, respectively. Dispersion curve calculations based on the transfer matrix method indicate that the directional emission is mediated by radiative waveguide modes. We show that the directional emission in a metaldielectric-metal structure is independent of the polarization of the incident light in contrast to plasmonic beaming structures, such as a subwavelength aperture surrounded by surface corrugations with a strong polarization dependence.