Showing papers by "José A. Ferrari published in 2000"
TL;DR: A simple method for visualization of phase objects placed between a printed two-dimensional periodic pattern and a CCD camera that has potential application for detection of gas leaks in industrial environments.
Abstract: We describe a simple method for visualization of phase objects The phase object is placed between a printed two-dimensional periodic pattern and a CCD camera The ray deflection that is due to the phase object distorts the image of the pattern This image is subtracted from a reference image and then, by squaring and low-pass filtering, a measurement of the two-dimensional refractive-index changes is obtained Because the optical system does not require special alignment or illumination, the method presented has potential application for detection of gas leaks in industrial environments
35 citations
TL;DR: A synchronous polarimeter was set up for the measurement of small rotation angles of the polarization plane of light, achieving an accuracy of the order of 10(-4) deg, or 5 mg/dl of glucose in a 1-cm light path.
Abstract: A synchronous polarimeter was set up for the measurement of
small rotation angles of the polarization plane of light. The
polarimeter is based on a polarizer–Faraday modulator–analyzer
structure with a synchronous detection scheme, which produces a linear
system response. The theoretical background is studied, and the
system performance is investigated experimentally. We achieved an
accuracy of the order of 10-4 deg, or 5 mg/dl of glucose
in a 1-cm light path.
29 citations
TL;DR: A novel optical sensor based on the Faraday effect for measuring ac that is proportional to the amplitude of the current is described and experimental results demonstrating the practicality of the procedure are presented.
Abstract: We describe a novel optical sensor based on the Faraday effect for
measuring ac. The sensing element is a piece of material of high
Verdet constant placed between polarizers. When the angle between
the polarizers differs by 45°, a signal of twice the frequency of the
ac is generated—in addition to the usual signal with the same
frequency as the current. The quotient of these two signals allows
a normalized output to be obtained that is proportional to the
amplitude of the current. Experimental results demonstrating the
practicality of the procedure are presented.
11 citations
TL;DR: A method for visualization of phase objects using incoherent illumination, which is based on the image enhancement due to an illumination gradient, is presented, which has potential application for gas-leak detection in industrial environments.
5 citations
TL;DR: A method for the generation of an axial phase dislocation on a wave front, which is induced by topological properties of polarized light, is presented and is shown to be useful for conversion of bright nondiffracting beams into dark nondiffractioning beams.
Abstract: We present a method for the generation of an axial phase dislocation on a wave front, which is induced by topological properties of polarized light This effect is shown to be useful for conversion of bright nondiffracting beams into dark nondiffracting beams Experiments showing the generation of dark nondiffracting beams have been performed
3 citations
1 citations