In this paper, we present a high accuracy laser range finder and velocimeter using ultra-fast time-to-digital converter (TDC). The system operation is based on the measuring the round-trip time of a narrow laser pulse. A low-dark current high-speed PIN photodiode is used to detect the triggered laser beam and to produce start signal. The pulsed laser diode generates 45W optical power at 30ns du...

We report the use of an all-solid-state ultrashort pulsed source specifically for two-photon microscopy at wavelengths shorter than those of the conventional Ti:Sapphire laser. Our approach involves sum-frequency mixing of the output from an optical parametric oscillator (λ= 1400-1640 nm) synchronously pumped by a Yb-doped fibre laser (λ= 1064 nm), with the residual pump radiation. This generat...

A study has been conducted in which HeLa cells are incubated with hematoporphyrin derivative (HpD) for 1 h (1 microgram/ml of HpD in PBS) to compare the use of continuous wave (CW) and pulsed laser (10 Hz repetition rate and 7-9 ns pulse width) light for photodynamic therapy. Cytotoxic effects on the cells are evaluated by the 3-(4,5-dimethyl-2-thiazolyl)-2-5-diphenyl-2H-tetrazolium bromide (MT...

Nickel ferrite nanoparticles are synthesized by pulsed laser ablation of corresponding bulk target in the double distilled water. Focused output of fundamental and third harmonics from pulsed Nd:YAG laser operating at 40 and 25 mJ/pulse energy respectively was allowed to irradiate the target. Produced colloidal solution was red in color and stable for several days. XRD, FTIR, VSM techniques are...

We propose a novel tuneable table-top optical source as an alternative to the free electron laser currently used for resonant infrared pulsed laser deposition of polymers. It is based on two-stage pulsed optical parametric amplification using MgO doped periodically poled lithium niobate crystals. Gain in excess of 10(6) in the first stage and pump depletion of 58% in the second stage were achie...

BACKGROUND Striae are frequent skin lesions that cause considerable aesthetic concern. The 1,064-nm long-pulsed Nd:YAG laser has been used to promote an increase in dermal collagen and is known to be a laser that has a high affinity for vascular chromophores. OBJECTIVE This study aims to verify the efficacy of the long-pulsed Nd:YAG laser in the treatment of immature striae. MATERIALS AND M...

A diode-side-pumped, high-energy, high-beam-quality, pulsed solid-state Nd3+:Y3Al5O12 (Nd:YAG) laser with a thermoelectric cooler (TEC) is investigated in this study. The pump laser was a pulsed laser diode array with maximum peak power of 15 kW. A 350 mJ laser pulse was obtained with a wavelength of 1064 nm, a pulse duration of 10 ns, a total electrical-to-optical efficiency of 7.5%, a relativ...

The ability to dynamically shape the spatial intensity profile of an incident laser beam enables new ways to modify and structure surfaces through pulsed laser processing. Here we describe a method to generate doughnutshaped beams from an input Gaussian source using a tunable acoustic gradient index (TAG) lens. The TAG lens is capable of modulating between focused beams and annular rings of var...

in this paper, a three-dimensional finite element model has been developed to simulate the laser-tig hybrid welding (hlaw) of stainless steel 1.4418 with thickness of 4 mm. transient temperature profile and dimensions of the fusion zone and heat affected zone (haz) during welding process are calculatedusing finite element method (fem) and were solved in the abaqus/standard software.the heat sou...