Using a new nanoplasmonic architecture and an optimized spacer, we observed the following: (a) the average fluorescence of an infrared dye (indocyanine green) is enhanced by 2970 fold uniformly (variation < 11%) over a large sample area and over a wide range of dye concentrations (380 to 380,000 molecule µm(-2)), laser excitation powers and laser beam sizes; and (b) for a single molecule placed...

We have studied stimulated emission in a random laser based on rhodamine 6G dye and TiO2 nanoparticles. At both small and large concentrations of nanoparticles, the minimum threshold was found at ultra-high concentrations of dye, 20 g L−1. With the increase in concentration of TiO2 nanoparticles, the threshold reaches its maximum at the transition from a weak-scattering regime to a strong-scatt...

Nail changes are present in about 50% of psoriasis patients and tend to be refractory to conventional treatments. Pulsed dye laser has emerged as an alternative therapy. Our aim is to evaluate the efficacy of pulsed dye laser in nail psoriasis and the impact of treatment on quality of life. Fourteen patients were treated in monthly sessions for three months. The outcome assesment was made by th...

In several recent experiments, isotropic lasing action was observed in paints that contain rhodamine 640 dye molecules in methanol solution as gain media and titania particles as optical scatterers. These so-called paint-on laser systems are extraordinary because they are highly disordered systems. The microscopic mechanism for laser activity and the coherence properties of light emission in th...

Hemangiomas are proliferating vascular harmatomas that can be superficial or deep. The natural history of hemangiomas includes proliferative, stationary, and involutional phases. Most cases resolve with minimal sequelae. During the rapid growth phase, hemagiomas may ulcerate. Therapy includes daily local wound care, topical antibiotics, and systemic steroids. Our patient failed to improve with ...

Laser-induced fluorescence measurements of OH have been performed in an atmospheric stoichiometric CH(4)/air flame and in a highly sooting propane flame. The measurements were realized with a single 6-nsec pulse from a frequency-doubled dye laser pumped by a Nd:YAG laser and with a spatial resolution of ~25 microm. This was achieved by imaging through a suitably chosen filter set a section of t...

The primary objective in this program is the development of an extremely stable, low-jitter, single-frequency cw dye laser for use in a variety of applications such as optical communication and ultrahigh-resolution spectroscopy, and for studying fundamental interactions between radiation and matter. During the past year we have been concerned with the short-term stabilization of commercially av...

In our search for efficient and photostable laser dyes, four new dyes with the basic structure of the commercial BODIPY laser dye PM567, with either an 8-diphenylene or an 8-p-triphenylene group, both substituted at the terminal polyphenylene position with an acetoxymethyl (dyes P2Ar1Ac and P3Ar1Ac, respectively) or a methacryloyloxymethyl group (dyes P2Ar1MA and P3Ar1MA, respectively), have be...

Dual beam thermal lens technique is successfully employed for the determination of absolute fluorescence quantum yield of rhodamine 6G laser dye in different solvents. A 532 nm radiation from a Q-switched Nd:YAG laser was used for the excitation purpose. The fluorescence quantum yield values are found to be strongly influenced by environmental effects. It has been observed that fluorescence yie...

New hybrid organic-inorganic dyes based on an azide-functionalized cubic octasilsesquioxane (POSS) as the inorganic part and a 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BDP) chromophore as the organic component have been synthesized by copper(I)-catalyzed 1,3-dipolar cycloaddition of azides to alkynes. We have studied the effects of the linkage group of BDP to the POSS unit and the degree of ...