Taurine-modified Ru(ii)-complex targets cancerous brain cells for photodynamic therapy.

The precision and efficacy of photodynamic therapy (PDT) is essential for the treatment of brain tumors because the cancer cells are within or adjacent to the delicate nervous system. Taurine is an abundant amino acid in the brain that serves the central nervous system (CNS). A taurine-modified polypyridyl Ru-complex was shown to have optimized intracellular affinity in cancer cells through accumulation in lysosomes. Symmetrical modification of this Ru-complex by multiple taurine molecules enhanced the efficiency of molecular emission with boosted generation of reactive oxygen species. These characteristic features make the taurine-modified Ru-complex a potentially effective photosensitizer for PDT of target cancer cells, with outstanding efficacy in cancerous brain cells.

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. In this review, we briefly introduce the optical nanofiber, its fabrication, and optical mode propagation within. We discuss recent progress on the integration of optical nanofibers into laser-cooled atom and vapor systems, paying particular attention to spectroscopy, cold atom cloud characterization, and optical trapping schemes. Next, a natural extension of this work to molecules is introduced. Finally, we consider several alternatives to optical nanofibers that display some advantages for specific applications.

Highly efficient optical filter based on vertically coupled photonic crystal cavity and bus waveguide.

We experimentally demonstrate a new optical filter design based on a vertically coupled photonic crystal (PhC) cavity and a bus waveguide monolithically integrated on the silicon-on-insulator platform. The use of a vertically coupled waveguide gives flexibility in the choice of the waveguide material and dimensions, dramatically lowering the insertion loss while achieving very high coupling efficiencies to wavelength scale resonators and thus allows the creation of PhC-based optical filters with very high extinction ratio (>10 dB).

Tapered optical fibers as tools for probing magneto-optical trap characteristics.

We present a novel technique for measuring the characteristics of a magneto-optical trap (MOT) for cold atoms by monitoring the spontaneous emission from trapped atoms coupled into the guided mode of a tapered optical nanofiber. We show that the nanofiber is highly sensitive to very small numbers of atoms close to its surface. The size and shape of the MOT, determined by translating the cold atom cloud across the tapered fiber, is in excellent agreement with measurements obtained using the conventional method of fluorescence imaging using a charge coupled device camera. The coupling of atomic fluorescence into the tapered fiber also allows us to monitor the loading and lifetime of the trap. The results are compared to those achieved by focusing the MOT fluorescence onto a photodiode and it was seen that the tapered fiber gives slightly longer loading and lifetime measurements due to the sensitivity of the fiber, even when very few atoms are present.