Nanophotonic structures can enhance light-mater interaction at nanoscales helping to improve the detection sensitivity of biosensors. In this work, we present a sandwich-type immunosensor by combining a nanophotonic resonant waveguide grating (RWG) structure and upconverting nanoparticles (UCNPs). UCNPs are used to label a target biomarker captured by capture antibody molecules immobilized on the surface of the RWG structure, which is used to enhance the upconversion fluorescence (UCF) of UCNPs through excitation resonance. The immunosensor has an extremely low limit of detection (LOD) in sub-fg/mL level and a detection range of six orders of magnitude and can be used to detect a variety of biomarkers such as cardiac troponin I, tau protein and phosphated-tau protein, etc. The LOD of the immunosensor is greatly reduced due to the increased UCF of UCNPs and the reduction of nonspecific adsorption of detection antibody-conjugated UCNPs on the RWG substrate surface.

A fully automated multi-target reactive magnetron sputtering (MS) process is presented in which real-time modeling and in situ standard or Mueller matrix ellipsometry is combined demonstrating growth of nanoscale multi-layer optical thin films having desired properties such as thickness, while observing properties such as index of refraction (n), extinction coefficient (k), and complex permittivity throughout growth. For each material layer isotropic or anisotropic properties as required can be modeled automatically in real-time, allowing for the development of hyperbolic metamaterials. In situ use of an RC2 ellipsometer from JA Woollam is presented, having a spectral range of 210nm - 2500nm. TEM measurements of the thin films are presented.

We have developed a gel-type surface-enhanced Raman scattering (SERS) sensor for the direct extraction of biomarkers from human skin and other sources. First, We used SERS-active sculptured Au nanoparticle substrates to explore how molecules move within hydroxyethyl cellulose (HEC) gels. This investigation aimed to understand the transport of biomarkers in gels and the feasibility of detecting them using SERS. Notably, the results revealed that HEC gels do not hinder SERS sensing. Additionally, the diffusion coefficient within the gels was found to be dependent on the molecular weight of the biomarkers. Then, we fabricated SERS-active sculptured thin-film dispersion gels by creating multilayer structures on mica. These multilayer structures significantly improved SERS performance due to the light confinement effect. Subsequently, we dispersed milled flakes into the gel. The resulting SERS-active flake dispersion gel holds promise for biosensing applications. Specifically, it allows for the direct collection of body fluids, such as sweat, from human skin.

Distributed feedback lasers (DFBs) using perovskite gain media can provide many unique properties such as single mode lasing and low pump thresholds. An important characteristic of lasing is the polarization because its control permits to manipulate the light. We present a study on optically pumped perovskite DFB gratings over a wide range of periods and duty cycles. Detailed analysis in the k-space of the lowest threshold lasing mode reveal the signature of a quasi-bound state in continuum (quasi-BIC) near Gamma-point, and additional radiative channels with mixed polarization states rising from the coupling of the counter propagating waves. The obtained results permit to map the far field distribution of polarization states and show the potential of a tuneable DFB based-BIC lasing.

Nature is a great source of inspiration for scientists and engineers to design and fabricate functional devices. Many animals and plants present a structural coloration, which is caused by the interaction of light with periodic structure, usually used in camouflage or to transmit information. Several natural surfaces show superwettability properties that allow self-cleaning abilities and water harvesting. Here, we show two examples of biomimetic coatings inspired by the cuticle of the Hoplia cerulea beetle and Stenocara beetle. The coatings were fabricated by using a simple and scalable approach based on layer-by-layer deposition of sol-gel solutions by spin coating. We developed a multilayer film with structural color by alternating a low refractive index material (silk fibroin) with a high refractive index layer (titania nanosheets). Inspired to the back of Namib desert beetle, we fabricated micropatterned surfaces through a controlled dewetting of bilayer films.

Structured light, powered by VCSEL light sources, is instrumental in numerous modern optical applications. Conventionally, optical systems rely on bulky configurations involving collimators and DOE devices, leading to increased weight and volume. Here, we proposed and designed an a-Si based multifunctional metasurface for structured light at 940 nm. By co-optimizing both phase and amplitude, we create a multifunctional metasurface, which offers a compact and lightweight alternative to conventional structured light systems. When combined with a VCSEL, we achieve structured light functionality with a working efficiency of 72.5% at 940 nm, accompanied by a wide field of view spanning 42.5 degrees. Initial findings from our design demonstrate significant performance improvements compared to conventional devices, highlighting its potential for widespread adoption across various domains.

Nanoimprint Lithography can be a cost-effective way for fast and accurate replication of nanostructures. Quality and high repeatability are key factors for the technique to be cost effective in the end. In-wafer and wafer-to-wafer variations of the imprinted nanostructures should be minimal while the stamp life should be as long as possible without compromising on quality. SCIL uses an inorganic sol-gel based resist that is not susceptible to aging and shows low to no haze with only little shrinkage after curing. Furthermore the resist doesn’t require heating or UV light for curing which is very beneficial for quality and repeatability which allows for a superior overlay alignment accuracy. Because of the technique used in combination with the resist and stamp materials it is also possible to directly imprint functional materials without the need of transfer etching into a substrate. SCIL Nanoimprint solutions not only provides machines and materials but provides a complete solution. With her own application lab and 2 high-volume production machines SCIL helps to optimize the processes from proof of concept up to pilot and high-volume production.

We report the development of a series of nanoparticle-free optical polymers with a high refractive index (n = 1.7 ~ 1.8) and high optical transparency for direct patterning and nanoimprint lithography applications. The polymer is ultraviolet-curable and contains no metal oxide fillers. It is one of the polymers with the highest refractive index value available amongst commercial filler-free materials. This new polymer can be patterned via photolithography and electron beam lithography, becoming the first high refractive index polymer with capabilities as a negative tone resist. These properties allow fast and easy prototyping and manufacturing of high refractive index optical devices, including microlens arrays, photonic integrated circuits, etc.

The main objective of this work is to use a mathematical model to predict the nanoparticle size. Lithium borate glass with Ag nanoparticles were synthetized by traditional melt-quenching technique. Morphology analysis is presented with TEM micrographs and X-ray diffraction patterns. UV–Vis-IR absorption spectra were recorded and used to estimate the nanoparticle size by Mie theory. Experimental mesurments agrees with the employeed theory.

Flat mirrors have been a consistent part of optical systems with a need to be included in devices such as microscopes and spectrometers Both the cases signify applications in which the limitations of flat mirrors are ever so important in the scope of modern optics, which has applications such as optical tweezers that require high focusing efficiency for trapping and rotation of particles Traditional invisible mirrors feature optical aberrations in off axis applications and further need multifunctional optical devices Metalenses are flat optics patterned with nanostructures, which have already given the potential for focusing and reflecting light without essential energy waste However, most conventional reflective metalenses are using a parabolic phase profile that reshapes the wavefront of the reflected beam The design based on lens models of the sphere leads to an often off the axis of propagation beam rays crossing the metalens nanoparticles, becoming specifically deviated upon them, with a loss of focal accuracy The paper presents a dielectric metalens based on the DMR structure and utilizes a dielectric Distributed Bragg Reflector ( to incorporate high reflection Accordingly, the so developed all dielectric reflector is aimed for the focusing of the incident electromagnetic waves having a wavelength in the visible range at a number of incidence angles, which, perhaps, may reduce major optical aberrations in off axis applications