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Gaussian beam
About: Gaussian beam is a research topic. Over the lifetime, 9071 publications have been published within this topic receiving 144730 citations.
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TL;DR: In this paper, a single-beam technique for measuring both the nonlinear refractive index and nonlinear absorption coefficient for a wide variety of materials is reported, including a comprehensive theoretical analysis.
Abstract: A sensitive single-beam technique for measuring both the nonlinear refractive index and nonlinear absorption coefficient for a wide variety of materials is reported. The authors describe the experimental details and present a comprehensive theoretical analysis including cases where nonlinear refraction is accompanied by nonlinear absorption. In these experiments, the transmittance of a sample is measured through a finite aperture in the far field as the sample is moved along the propagation path (z) of a focused Gaussian beam. The sign and magnitude of the nonlinear refraction are easily deduced from such a transmittance curve (Z-scan). Employing this technique, a sensitivity of better than lambda /300 wavefront distortion is achieved in n/sub 2/ measurements of BaF/sub 2/ using picosecond frequency-doubled Nd:YAG laser pulses. >
7,717 citations
TL;DR: A simple yet highly sensitive single-beam experimental technique for the determination of both the sign and magnitude of n(2), where the sample is moved along the z direction of a focused Gaussian beam while the repetitively pulsed laser energy is held fixed.
Abstract: We present a simple yet highly sensitive single-beam experimental technique for the determination of both the sign and magnitude of n2. The sample is moved along the z direction of a focused Gaussian beam while the repetitively pulsed laser energy is held fixed. The resultant plot of transmittance through an aperture in the far field yields a dispersion-shaped curve from which n2 is easily calculated. A transmittance change of 1% corresponds to a phase distortion of ≃ λ/250. We demonstrate this method on several materials using both CO2 and Nd:YAG laser pulses.
2,254 citations
TL;DR: The thresholds for several effects in picosecondlaser-induced phase transformation on silicon-crystal surfaces are calibrated with a simple technique for in situ measurements of pulsed Gaussian-beam spot sizes.
Abstract: A simple technique for in situ measurements of pulsed Gaussian-beam spot sizes is reported. This technique is particularly useful for measurements on highly focused beam spots. It can also be used for absolute calibration of the threshold-energy fluences for pulsed-laser-induced effects. The thresholds for several effects in picosecond-laser-induced phase transformation on silicon-crystal surfaces are calibrated with this technique.
1,509 citations
TL;DR: In this paper, the authors consider the possibility that the two fibers of different dimensions are separated in longitudinal direction and are tilted or offset with respect to each other, and the trade-off between slice tolerances with regard to tilt and offset is expressed as an uncertainty principle.
Abstract: This paper analyses losses caused by the misalignment of two fibers joined in a splice. We consider the possibility that the two fibers of different dimensions are separated in longitudinal direction and are tilted or offset with respect to each other. Central to our discussion is the observation that the modes of single-mode fibers are very nearly gaussian in shape regardless of the fiber type step-index or graded-index. The splice losses are thus related to the corresponding losses of gaussian beams. We specify the relation between the actual mode field and the gaussian beam that matches this field optimally. The trade-off between slice tolerances with respect to tilt and offset is expressed as an “uncertainty principle. “ Because of the near-gaussian nature of single-mode fiber fields, our results are immediately applicable to the excitation of single-mode fibers by gaussian-shaped laser beams.
1,134 citations
TL;DR: In this paper, the use of Airy beams is exploited for transport of particles along curved paths without moving the light beam, a technique that seems poised for many microfluidic applications especially in the biological sciences.
Abstract: Scientists exploit the use of Airy beams — an unusual class of optical waves — in optical manipulation. The beam can be used to transport particles along curved paths without moving the light beam, a technique that seems poised for many microfluidic applications especially in the biological sciences.
1,047 citations