Absorption-induced transmission in plasma microphotonics.

Ionised gas, i.e., plasma, is a medium where electrons-ions dynamics are electrically and magnetically altered.

Fast and efficient nanoparticle trapping using plasmonic connected nanoring apertures.

The manipulation of microparticles using optical forces has led to many applications in the life and physical sciences. To extend optical trapping towards the nano-regime, in this work we demonstrate trapping of single nanoparticles in arrays of plasmonic coaxial nano-apertures with various inner disk sizes and theoretically estimate the associated forces. A high normalized experimental trap stiffness of 3.

Fano-Resonant, Asymmetric, Metamaterial-Assisted Tweezers for Single Nanoparticle Trapping.

Plasmonic nanostructures overcome Abbe's diffraction limit to create strong gradient electric fields, enabling efficient optical trapping of nanoparticles. However, it remains challenging to achieve stable trapping with low incident laser intensity. Here, we demonstrate Fano resonance-assisted plasmonic optical tweezers for single nanoparticle trapping in an array of asymmetrical split nanoapertures on a 50 nm gold thin film.

Simple, narrow, and robust atomic frequency reference at 993 nm exploiting the rubidium (Rb) 5S to 6S transition using one-color two-photon excitation.

We experimentally demonstrate a one-color two-photon transition from the 5S ground state to the 6S excited state in rubidium (Rb) vapor using a continuous wave laser at 993 nm. The Rb vapor contains both isotopes (Rb and Rb) in their natural abundances. The electric dipole-allowed transitions are characterized by varying the power and polarization of the excitation laser.

Fiber-bundle-basis sparse reconstruction for high resolution wide-field microendoscopy.

In order to observe deep regions of the brain, we propose the use of a fiber bundle for microendoscopy. Fiber bundles allow for the excitation and collection of fluorescence as well as wide field imaging while remaining largely impervious to image distortions brought on by bending. Furthermore, their thin diameter, from 200-500 m, means their impact on living tissue, though not absent, is minimal.

Fluorescence from a single Symbiodinium cell.

The partnership between coral and its algal symbionts, Symbiodinium, is crucial to the global environment. Yet, the regulatory process within the photosynthetic machinery of Symbiodinium is still not clearly understood. Here, we studied the influence of light stress from focussed red and blue lasers on single Symbiodinium cells.

All-optical nanopositioning of high-Q silica microspheres.

A tunable, all-optical, coupling method is realised for a high-Q silica microsphere and an optical waveguide. By means of a novel optical nanopositioning method, induced thermal expansion of an asymmetric microsphere stem for laser powers up to 211 mW is observed and used to fine tune the microsphere-waveguide coupling. Microcavity displacements ranging from (0.

Four-wave mixing parametric oscillation and frequency comb generation at visible wavelengths in a silica microbubble resonator.

Frequency comb generation in microresonators at visible wavelengths has found applications in a variety of areas such as metrology, sensing, and imaging. To achieve Kerr combs based on four-wave mixing in a microresonator, dispersion must be in the anomalous regime. In this Letter, we demonstrate dispersion engineering in a microbubble resonator (MBR) fabricated by a two-CO laser beam technique.

Highly tunable plasmonic nanoring arrays for nanoparticle manipulation and detection.

The advancement of trapping and detection of nano-objects at very low laser powers in the near-infra-red region (NIR) is crucial for many applications. Singular visible-light nano-optics based on abrupt phase changes have recently demonstrated a significant improvement in molecule detection. Here, we propose and demonstrate tunable plasmonic nanodevices, which can improve both the trapping field enhancement and detection of nano-objects using singular phase drops in the NIR range.

Degenerate four-wave mixing in a silica hollow bottle-like microresonator.

A hollow, bottle-like microresonator (BLMR) was fabricated from a microcapillary with a nearly parabolic profile. From simulations at 1.55 μm the fundamental bottle mode is shown to be in the anomalous dispersion regime, while the conventional whispering gallery mode, confined to the center of the BLMR, is in the normal dispersion regime.

Coupled-mode-induced transparency in aerostatically tuned microbubble whispering-gallery resonators.

Coupled-mode-induced transparency is realized in a single microbubble whispering-gallery mode resonator. Using aerostatic tuning, we find that the pressure-induced shifting rates are different for different radial order modes. A finite element simulation considering both the strain and stress effects shows a GHz/bar difference, and this is confirmed by experiments.

Contributed review: optical micro- and nanofiber pulling rig.

We review the method of producing adiabatic optical micro- and nanofibers using a hydrogen/oxygen flame brushing technique. The flame is scanned along the fiber, which is being simultaneously stretched by two translation stages. The tapered fiber fabrication is reproducible and yields highly adiabatic tapers with either exponential or linear profiles.

Selective particle trapping and optical binding in the evanescent field of an optical nanofiber.

The evanescent field of an optical nanofiber presents a versatile interface for the manipulation of micron-scale particles in dispersion. Here, we present a detailed study of the optical binding interactions of a pair of 3.13 μm SiO(2) spheres in the nanofiber evanescent field.

Quasi-droplet microbubbles for high resolution sensing applications.

Optical properties and sensing capabilities of fused silica microbubbles were studied numerically using a finite element method. Mode characteristics, such as quality factor (Q) and effective refractive index, were determined for different bubble diameters and shell thicknesses. For sensing applications with whispering gallery modes (WGMs), thinner shells yield improved sensitivity.

Spectroscopy, manipulation and trapping of neutral atoms, molecules, and other particles using optical nanofibers: a review.

The use of tapered optical fibers, i.e., optical nanofibers, for spectroscopy and the detection of small numbers of particles, such as neutral atoms or molecules, has been gaining interest in recent years.

Single-input spherical microbubble resonator.

A single-input whispering gallery optical microbubble resonator is presented. Spherical microbubbles with diameters less than 100 μm, micrometer-sized wall thicknesses, and a single opening or input were fabricated by heating the tapered tip of a pressurized glass capillary using a CO(2) laser. Optical whispering gallery modes with Q factors of ∼10(5) were obtained.

Efficient polarization analyzer for Lyman(alpha) radiation.

A new efficient polarization analyzer for Lyman(alpha) radiation is described and compared with previously reported instruments.