Showing papers in "Optics and Lasers in Engineering in 2002"

TL;DR: In this paper, the authors reviewed the current available semiconductor laser sources for spectroscopy in the near and mid-infrared spectral region based upon gallium arsenide, indium phosphite, antimonides and lead-salt containing compounds.

TL;DR: In this paper, the authors reviewed the achievements about the fiber Bragg gratings (FBG) as a strain and temperature sensor and described the potential applications of FBG sensors for applications in the field of geophysics and its expected development in the near future.

TL;DR: In this paper, a phase-shifting Mach-Zehnder interferometer is used for recording four-quadrature phase shifted off-axis holograms with a CCD camera.

TL;DR: In this paper, a tandem in-fibre Bragg-grating (FBG)/extrinsic Fabry-Perot interferometric sensor (EFPI) system with improved accuracy has been used to facilitate simultaneous strain and temperature measurement for advanced 3D braided composite materials using fiber-optic sensor technology.

TL;DR: In this article, the first field measurements of volcanic gases using mid-IR difference frequency laser spectroscopy were reported at the summit crater of Masaya volcano, Nicaragua, with the gases being drawn into a multi-pass cell and measured at reduced pressure.

TL;DR: This work attempts an objective comparison in terms of performance and execution speed of some of the best known phase unwrapping algorithms.

TL;DR: In this article, preliminary results on the laser ignition of a jet diffusion flame with jet flow rates ranging from 35 (Re =1086) to 103 cm 3 /s ( Re =3197) were reported.

TL;DR: In this article, the emissions of sulphur dioxide from the Italian volcanoes Mt. Etna and Stromboli were studied in ship-borne underpasses of their plumes.

TL;DR: In this paper, a low-coherence Linnik interference microscope using high numerical aperture optics has been constructed using a tungsten halogen lamp and Kohler illumination, with separate control over field and aperture stops.

TL;DR: In this paper, a simple, compact and low-cost laser Doppler vibrometer is presented, which is composed of a laser diode (9mm in diameter, 2 ¾g of weight, emitting at 825nm) and by a two-lens optical system designed to focus the laser radiation on the vibrating target.

TL;DR: In this article, a 1.5 kW CO2 laser was used to perform different experiments in which, the influence of some processing parameters (average power, assist gas pressure) on the geometry and quality of the cut was studied.

TL;DR: In this paper, the applicability of moire interferometry and microscopic magnification to the visualization of the heterogeneous nature of the plastic strains in a polycrystalline material is considered.

TL;DR: In this paper, an optoelectronic system is presented that is used to measure the 3D vector components of a vibrating object by combination of three different measurements, and the shape of the object is determined by subtraction of the phases of the wavefronts recorded at the two different wavelengths.

TL;DR: In this article, a procedure is described whereby the characterization of isotropic and anisotropic laminae is carried out by full-field measurement of the surface rotations under proper flexural loads.

TL;DR: In this article, a review of the activities and results of the last 10 years in the field of Optical Spectroscopy for Geophysical Gas Monitoring is given, and a comparison between the results from the DIAL and passive techniques (DOAS and correlation spectroscopy) are performed.

TL;DR: In this article, the Nd-doped concentration in Nd:YVO 4 crystal samples was investigated under high pumping power of laser diode and the results showed that the optimum Ndd-decrease was about 0.5 at% under a 30 W pumping power.

TL;DR: In this article, a continuous wave Doppler velocimeter has been developed for remote estimation of the volume of polluted water and gaseous discharges using an actively stabilized ring dye laser.

TL;DR: Considering the influence of the cut front shape on the absorption of the laser beam, a simplified 2D mathematic model is developed based on a pulsed laser vaporization cut process in this paper.

TL;DR: In this paper, the proportions of H 2 O, CO 2, CO and SO 2 in gas emissions from Oldoinyo Lengai, the world's unique, active carbonatite volcano, were measured.

TL;DR: The quantitative approach to 3D reconstruction of refractive index inhomogeneity of static phase object is presented and the results prove high performance of the proposed measuring procedure.

TL;DR: In this article, a comparison between the results obtained by two methods, the fringe shift method and phase analysis method, is presented, and a comparison of the two methods is made.

TL;DR: This eye-tracking interface can determine the position of a subject's pupil and map that position into a display point on a computer screen and compute the pupil size and location data versus the average brightness and contrast of a VR video image in real time.

TL;DR: A survey of the problems typically encountered in uncertainty calculations when vibrations are measured or accelerometers calibrated by laser interferometry is given and it is shown how a model function of simple structure can be established for the usually complex relationship between the output quantity and various influence quantities.

TL;DR: In this paper, laser removal of small 1 μm sized copper, gold and tungsten particles from silicon wafer surfaces was carried out using ultraviolet radiation at 266 nm generated by Nd:YAG harmonic generation.

TL;DR: In this article, a discussion of cavity-enhanced absorption spectrometers, operating with near-infrared diode lasers, is presented. And the operating principle as well as the achievable performance of these devices, also compared to more traditional apparatus, based on the multiple reflection cells.

TL;DR: The general measurement procedure and the equipment used for the determination of structural intensity fields, which give transfer path of the vibration energy within a structure, are described and various measurement results are shown.

TL;DR: In this article, the authors presented the results obtained and the first interpretation of the obtained displacements associated with the December 23, 1993 earthquake (magnitude Mb = 5.0) produced between Adra and Berja cities.