We present an integrated photoacoustic and ultrasonic three-dimensional (3-D) volumetric imaging system based on a two-dimensional (2-D) matrix array ultrasound probe. A wavelength-tunable dye laser pumped by a Q-switched Nd:YAG laser serves as the light source and a modified commercial ultrasound imaging system (iU22, Philips Healthcare) with a 2-D array transducer (X7-2, Philips Healthcare) d...

Nowadays in highly competitive precision industries, the micromachining of advanced engineering materials is extremely demand as it has extensive application in the fields of automobile, electronic, biomedical and aerospace engineering. The present work addresses the modeling and optimization study on dimensional deviations of square-shaped microgroove in laser micromachining of aluminum oxide ...

We have developed a two-dimensional (2D) Fourier-transform femtosecond spectroscopy technique for the visible spectral region. Three-pulse photon echo signals are generated in a phase-matched noncollinear four-wave mixing box geometry that employs a 3-kHz repetition-rate laser system and optical parametric amplification. Nonlinear signals are fully characterized in amplitude and phase by spectr...

When performing laser-induced plasma spectroscopy for elemental analysis, the analyte signal-to-noise ratio increased from four to over fifty if the plume was reheated by a dye laser pulse tuned to resonant absorption. Time-resolved studies showed that the enhancement was not due to resonance photoionization. Rather, efficient and controlled rekindling of a larger plume volume was the key mecha...

In this paper, we report the experimental results of a pulsed flash lamped Nd:YAG laser at wavelength of 1064 nm and Qswitched by Cr4+:YAG solid state saturable absorber. We have obtained the output energy (E) and pulse-width ( p τ ) of this laser for various initial transmissions of this saturable absorber. Furthermore, the effect of reflectivity of the output coupler (R), diameter of the rod ...

We report a simple extension of the Z-scan technique where pulse trains characteristic of a Q-switched and mode-locked Nd:YAG laser are employed to investigate the dynamics of third-order optical nonlinearities. The method allows discriminating between fast and accumulative nonlinearities, and was applied to the investigation of liquid samples, namely chloroform, benzene, and a solution of Disp...

The duration of pulses generated from a simple colliding-pulse mode-locked cw dye laser is measured as a function of cavity-mirror dispersion. The optimum amount of mirror dispersion of ø (omega) congruent with + 1.8 x 10(-28) sec(2) and a suitable mirror coating for upchirp compensation are identified. The adjustment of mirror dispersion only, without additional dispersive elements, generates ...

A tunable ArF* (193-nm) excimer source is described that produces over 125 mJ/pulse (peak) at 10 pulses/sec. This device has a spectral width of less than 2 cm(-1) and a demonstrated tunability of nearly 320 cm(-1) from 192.8 to 193.9 nm. Tunability, bandwidth, and mode control are achieved by injecting the fourth anti-Stokes line (in H(2)) of a frequency-doubled dye laser into an ArF* excimer-...

introduction: controversial results have been reported when organic acids, ultrasonic instruments and laser techniques were used to remove smear layer in endodontic treatments. the aim of this study was to evaluate the effect of removing debris and smear layer by er,cr:ysgg laser irradiation on the apical leakage of retrograde cavities. materials and methods: in this ex vivo study, 24 extracted...