Plasmonic nanostructures can enhance spontaneous emission rates by orders of magnitude, making solid-state single-photon emitters practical for quantum technologies. Strong confinement of the electric field allows plasmonics to achieve greater enhancement than dielectric cavities. Using nanopatch antenna structures and ultra-low loss epitaxial silver films, we demonstrated record brightness of single nitrogen vacancy centers. These results were extended to show that plasmonic enhancement could theoretically produce single photons at THz rates from a quantum emitter. By enhancing the emission rate to a sufficient degree, plasmonics will produce photons faster than the dephasing rate, thereby generating indistinguishable photons at elevated temperatures.

Biofilm is produced when a bacteria’s environment becomes hostile and uses biofilm as protection from the environment. In this work, we investigate the biofilm formation of Bacillus subtilis bacteria within minimal biofilm-promoting media (MSgg media) and how optical trapping affects bacteria aggregation and biofilm development. In low-nutrition media, B. subtilis secretes a glue-like substance and ultimately forms a biofilm. We use an optical tweezers system to observe bacteria division, reorganization, aggregation, and clustering with and without optical trapping. The study of optically controlled biofilm formation enables us to create novel models for inducing and suppressing biofilm development with lasers.

Full Poincaré beams, formed of all polarization states represented on a Poincaré sphere, have been intensively studied as an analogous topological quasiparticle, referred an optical skyrmion, in fundamental physics and advanced technologies. Néel-, Bloch-, and anti- skyrmions have been discovered in magnetic materials and liquid crystals, however, the generation of optical skyrmions is still an emerging topic in its infancy. In this study, we propose a robust and cost-saving system, formed simply of a single spatial light modulator with a self-referenced interferometric configuration, and waveplates, which enables the generation of some types of optical skyrmions.

In developing micro- and nanodevices, stiction between their parts is a well-known problem. It is caused by the finite-temperature analogue of the quantum electrodynamical Casimir–Lifshitz forces, which are normally attractive. Repulsive Casimir–Lifshitz forces have been realized experimentally, but their reliance on specialized materials severely limits their applicability and prevents their dynamic control. Here we demonstrate that repulsive critical Casimir forces, which emerge in a critical binary liquid mixture upon approaching the critical temperature, can be used to counteract stiction due to Casimir–Lifshitz forces and actively control microscopic and nanoscopic objects with nanometre precision.

We study far from equilibrium systems through investigating how groups of bacteria behave when other bacteria are present in the system and when barriers are introduced. For these studies we use structured light to fabricate microscopic structures for optical trapping and cell studies using two photon photopolymerization process. Structured light is created using spatial light modulator and correct for wavefront distortions in-situ providing aberration corrected system. This system is used to enable production of simple holographic optical tweezers apparatus with as many as 50 individual foci to create complex 3D microstructures. These structures can induce the collective behaviour of bacteria.

Azo-polymers enable the develop rewritable engineered optical materials with exotic physical properties unattainable in natural materials via photo-induced reversible surface reliefs through trans-cis-trans photoisomerization. The coherent superposition of optical vortices with negative and positive topological charges of ±ℓ, referred a petal-beam, exhibits an exotic spatial form with 2|ℓ| petals. In this work, we report on the first demonstration of the surface structures, reflecting full geometric parameters (rotating direction, topological charge, initial and azimuthal phase) of the irradiated petal-beam, of azo-polymers through the irradiation of a temporally spinning petal-beam with circular polarization.

We demonstrate the laser-induced forward transfer of fluorescent liquid droplets with viscosity 100 times higher than that of water. The optical vortex allows the high-definition direct-print of uniform microdroplets with no satellite droplets at desired locations within 10% positioning error, while the Gaussian laser produces only irregular printed droplets with many undesired satellite droplets. The printed droplets act as a laser with whispering-galley-modes. We discuss the droplet formation mechanism from the viewpoint of laser-induced cavitation based on the observation with a high-speed camera.

Biological studies are increasingly using optical forces to study cellular behavior and intracellular interactions. In this talk, we discuss the use of optically generated forces in biomedical treatment and diagnostics with specific reference to traumatic brain injury (TBI). Our biophotonic workstation includes optical tweezers, quantitative phase microscopy, fluorescence imaging, and laser-induced shockwaves to study cellular damage. We discuss our studies on astrocyte damage repair mechanisms as well as how the optical toolbox enables the study of intracellular signaling and cellular dynamics and anatomy.

Light propelled micro-machines yield important advantages. While most other propulsion mechanisms require some kind of fuel in the surrounding medium, light acts as an external energy source which enables high spatio-temporal control. In our novel approach the actuation emerges from refraction of light on micro-machines with an asymmetric shape and refractive index profiles. The artificial micro-machines are fabricated by femtosecond laser lithography by two-photon polymerization which enables high precision and flexibility. We demonstrate and compare the propulsion of light propelled particles with different geometries and refractive index gradients.

We recently developed a dynamic light-engineering platform shapeshifting diffractive optical elements for on-demand optical functionality. Design methodology and experimental results will be presented.

Plasmonic materials that show strong electromagnetic field confinement effects hybridized with atomically thin transition metal dichalcogenides exhibit strong light–matter interactions. Herein, such a system has been designed in the form of a silicon nanowire (SiNW)/ gold nanoparticles (AuNP)/ molybdenum disulfide (MoS2) nanofilms heterostructure (SiNW/AuNP/MoS2), which exhibits excellent photocatalytic hydrogen evolution reactions. The absorption frequency of 2D-MoS2, the antireflection frequency of 1D-SiNW, and the resonance frequency of the 0D-AuNP, respectively, match with the visible range, indicating that the material effectively utilizes solar energy. Additionally, an optimal MoS2 structure that is a hybrid of both 1T and 2H phases was prepared with high reproducibility using facile pyrolysis, with the structure benefiting the hydrogen evolution performance of the material. Moreover, the silicon nanowire substrate exhibits high antireflection properties due to light-trapping effects, achieving 95% for the visible light absorption. By introducing silicon nanowire, a p–n junction is formed at the MoS2/Silicon nanowire interface that facilitates charge separation. The 1D silicon nanowire/0D gold nanoparticles /2D MoS2 nanofilms exhibits a high hydrogen generation rate of 246 mmol g−1 h−1. Overall, a low-cost, eco-friendly hybrid-structured catalyst was designed that exhibits excellent HER performance.