Related papers: High-reflectance III-nitride distributed Bragg ref…
Strong interference in ultrathin film semiconductor absorbers on metallic back reflectors has been shown to enhance the light harvesting efficiency of solar cell materials. However, metallic back reflectors are not suitable for tandem cell…
We present an approach to the molecular-beam epitaxy of high-Q planar GaAs-based microcavities in which the AlGaAs high-index layers of the distributed Bragg reflectors (DBRs) are replaced by short-period GaAs/AlAs superlattices (digital…
We report on the design, realization and characterization of optically pumped micropillar lasers with low-absorbing Al$_{0.2}$Ga$_{0.8}$As/Al$_{0.9}$Ga$_{0.1}$As dielectric Bragg reflectors (DBRs) instead of commonly used GaAs/AlGaAs DBRs.…
High quality n-type AlGaAs distributed Bragg reflectors (DBRs) and lnGaAs multiple quantum wells were successfully monolithically grown on 4-inch off-cut Ge (100) wafers. The grown structures have photoluminescence spectra and reflectance…
We study the optical reflectivity of three-dimensional (3D) photonic band gap crystals with increasing thickness. The crystals consist of GaAs plates with nanorod arrays that are assembled by an advanced stacking method into high-quality 3D…
In-situ measurement is a key feature to better understand and precisely control the growth of complex structures, such as vertical-cavity surface-emitting lasers. In this work, we are showing the precise measurement of optical indices of…
High-quality Al0.37In0.63N layers have been grown by reactive radio-frequency (RF) sputtering on sapphire, glass and Si (111) at low substrate temperature (from room temperature to 300{\deg}C). Their structural, chemical and optical…
High-reflectivity mirrors in the mid-infrared (MIR) range are essential for next-generation optoelectronic devices but are still constrained by strain accumulation, poor thermal conductivity, and growth instability of thick multi-alloy…
This study presents an optimized hybrid design integrating a distributed Bragg reflector (DBR) and a TiO2 nanocylinder metasurface to enhance light extraction efficiency (LEE) and beam directionality(narrow divergence angle) in…
This work studies the effect of four different types of buffer layers on the structural and optical properties of InGaN layers grown on Si(111) substrates and their correlation with electrical characteristics. The vertical electrical…
Aluminum nitride (AlN) is an emerging material for integrated quantum photonics with its excellent linear and nonlinear optical properties. In particular, its second-order nonlinear susceptibility $\chi^{(2)}$ allows single-photon…
Highly reflective mirrors are indispensable components in a variety of state-of-the-art photonic devices. Typically used, bulky, multi-layered distributed Bragg (DBR) reflectors are limited to lattice-matched semiconductors or nonconductive…
Adding sufficient tensile strain to Ge can turn the material to a direct bandgap group IV semiconductor emitting in the mid-infrared wavelength range. However, highly strained-Ge cannot be directly grown on Si due to its large lattice…
Sub-wavelength dielectric gratings (SWG) have emerged recently as a promising alternative to distributed-Bragg-reflection (DBR) dielectric stacks for broadband, high-reflectivity filtering applications. A SWG structure composed of a single…
Series of GaN/AlN superlattices (SLs) with various periods and the same thicknesses of GaN quantum wells and AlN barriers have been investigated. X-ray diffraction, photoluminescence (PL) and transmission electron microscopy (TEM)…
We discuss the applicability of holographically recorded gratings in photopolymers and holographic polymer-dispersed liquid crystals as neutron optical elements. An experimental investigation of their properties for light and neutrons with…
Color can originate from wavelength-dependence in the absorption of pigments or the scattering of nanostructures. While synthetic colors are dominated by the former, vivid structural colors found in nature have inspired much research on the…
This paper presents the development of a superconducting nanowire single-photon detector (SNSPD) integrated into a distributed Bragg reflector (DBR) with a design center wavelength of 830 nm and a width of 200 nm. This SNSPD is made of a…
Most III-nitride semiconductors are grown on non-lattice-matched substrates like sapphire or silicon due to the extreme difficulty of obtaining a native GaN substrate. We show that several layered transition-metal dichalcogenides are…
GaN-nanorods grown on Si(111) substrates are found strain- and defect-free as characterized by micro Raman spectroscopy, secondary electron (SE) and cathode-luminescence (CL) imaging. The matrix supporting the nanorods bears the brunt of…