Experimental measurements of the intensity fluctuations and the associated power spectra for the pump (argon) laser and the secondary (dye) laser show that the secondary laser follows pump fluctuations when operated far above threshold but acts as a low-pass filter when operated close to threshold. The experimental results are well explained by a laser model that accounts for pump fluctuations ...

Fluorescence resonance energy transfer represents a mechanism to transport light energy at the nano-scale as is exemplified by nature’s light harvesting complexes. Here we used DNA origami to arrange fluorophores that transport excited state energy from an input dye to an output dye. We demonstrate that energy transfer paths can be controlled on the single-molecule level by the presence of a “j...

BACKGROUND So far, pulsed dye lasers have been regarded as the gold standard in the treatment of port-wine stains (PWS). Recently, intense pulsed light (IPL) has been reported to achieve more pronounced fading in some patients. OBJECTIVES To evaluate the efficacy and the side effects of IPL treatment of PWS in a direct comparison to the short-pulsed dye laser (SPDL) and the long-pulsed dye la...

The aim of this study was to evaluate the effects of the laser radiation (685 nm) associated with photosensitizers on viability of different species of Candida genus. Suspensions of Candida albicans, Candida dubliniensis, Candida krusei and Candida tropicalis, containing 10(6) viable cells per milliliter were obtained with the aid of a Neubauer's chamber. From each species, 10 samples of the ce...

The feasibility of implementing a two-color laser-induced fluorescence (LIF) technique to study thermal transport at the microscale is investigated. Temperature-sensitive (Rhodamine B) and temperature-insensitive (Sulforhodamine-101) fluorescent dyes are used in tandem to determine fluid temperature with high accuracy and low noise using a pulsed Nd:YAG laser as an illumination source. While th...

In this paper, we present a laser-induced photoacoustic study on the photostability of laser dye Coumarin 540 doped in PMMA matrix and modified by the incorporation of low-molecular weight additives. The dependence of photostability of the dye on various experimental conditions, such as nature of solvents, incident optical power and dye concentration, is investigated in detail. The activation r...

:the output can be dramatically improved by isolating the dye cell thermally from the flashlamp and ensuring uniform axially symmetric flow of the dye throughout the cell. A quadraxial laser tube in which the dye cell is surrounded by an evacuated annulus to provide thermal isolation and is terminated by specially designed end caps to provide uniform injection and removal of the dye solution wa...

This paper presents a unique optical technique that utilizes the reabsorption and emission of two fluorescent dyes to accurately measure film thickness while minimizing errors caused by variations in illumination intensity and surface reflectivity. Combinations of dyes are selected that exhibit a high degree of emission reabsorption and each dye concentration is adjusted to create an optically ...

Rhodamine 6G and Rhodamine B dye mixture doped polymer optical fiber amplifier (POFA), which can operate in a broad wavelength region (60 nm), has been successfully fabricated and tested. Tunable operation of the amplifier over a broad wavelength region is achieved by mixing different ratios of the dyes. The dye doped POFA is pumped axially using 532 nm, 10 ns laser pulses from a frequency doub...

A two-stage dye amplifier design has been developed to amplify tunable, blue-green, subpicosecond dye laser pulses which are generated from a hybrid synchronously modelocked dye oscillator directly (800 fs) or shorter to 200 fs by a fiber compressor stage. This system has achieved single pulse energies of 2 mJ, with an amplified spontaneous emission content of less than 0.1%. Using 40 mJ of the...