Novel chitosan-ZnO-graphene oxide hybrid composites were prepared using a one-pot chemical strategy, and their dye adsorption characteristics and antibacterial activity were demonstrated. The prepared chitosan and the hybrids such as chitosan-ZnO and chitosan-ZnO-graphene oxide were characterized by UV-Vis absorption spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, scan...

Microfluidic dye lasers (MDL) have recently emerged as promising candidates to facilitate the fusion of optics and fluidics at the microscale. Their primary advantage over gas or solid state lasers is the inherent wavelength tunabililty which can be achieved by changing the type of dye used, the dye concentration, or the host solution. Here, we report on the design and characterization of a MDL...

Spurious sidebands observed in the noise spectrum of colliding-pulse mode-locking dye lasers result from coupling of the longitudinal mode beating modulations of the (argon-ion) pump laser with the dye laser. We achieve a 50-dB amplitude noise reduction at the mixing frequencies by inserting a single-frequency étalon in the argon-laser cavity. Furthermore, we find the amplitude noise of the col...

We have demonstrated a guided-mode resonance filter (GMRF) whose properties are tunable with laser illumination through the incorporation of a nonlinear dye. Laser illumination causes a change in the refractive index of the dye-doped portion of the structure, leading to controlled tuning of the GMRF reflectance spectrum. Changes in the refractive index of dye-doped regions are proportional to t...

An amplified cholesteric liquid crystal (CLC) laser performance is demonstrated by utilizing a binary-dye mixture (with 62 wt% DCM and 38 wt% PM597) as the active medium and an external stable resonator. The measured results show that the laser efficiency is enhanced as compared to the highest efficiency of each individual dye. Furthermore, using such an active CLC in an external stable resonat...

Since 1983, the current network of NASA Satellite Laser Ranging (SLR) stations used an Nd:YAG oscillator cavity in an active-passive configuration to generate 150-200 psec (2mj) 1064nm pulses for satellite ranging. This cavity (active-passive) used a liquid (chlorobenzene) dye cell as the passive saturable absorber. The dye consisted of Exciton (Kodak-9740) Q-Switch I dye and monochlorobenzene ...

We present the first observation, to our knowledge, of lasing from a levitated, dye droplet. The levitated droplets are created by computer controlled pico-liter dispensing into one of the nodes of a standing ultrasonic wave (100 kHz), where the droplet is trapped. The free hanging droplet forms a high quality optical resonator. Our 750 nL lasing droplets consist of Rhodamine 6G dissolved in et...

introduction: the ultimate goal of endodontic treatment is to eliminate the bacterial infection in the root canal system. while mechanical debridement combined with chemical irrigation removes the bulk of microorganisms, residual bacteria are readily detectable in approximately one-half of teeth just prior to obturation. laser light can be used to destroy bacteria. this in vitro study was perfo...

We investigated the effects of lasers irradiation on the exposed dentinal tubule. Human tooth specimens with exposed dentinal tubule orifices were used. Three types of lasers (CO(2) laser, Er:YAG laser and Ga-Al-As laser) were employed. The parameters were 1.0 W in continuous-wave mode with an irradiation time of 30 s for the CO(2) laser, 30 mJ in continuous-wave mode with an irradiation time o...

5. Cliff S, Felix RH, Singh L, Harland CC. The successful treatment of lupus pernio with the flashlamp pulsed dye laser. J Cutan Laser Ther. 1999;1:49--52. 6. Roos S, Raulin C, Ockenfels HM, Karsai S. Successful treatment of cutaneous sarcoidosis lesions with the flashlamp pumped pulsed dye laser: a case report. Dermatol Surg. 2009;35:1139--40. 7. O’Donoghue NB, Barlow RJ. Laser remodelling of ...