Topic
Signal beam
About: Signal beam is a research topic. Over the lifetime, 1881 publications have been published within this topic receiving 20717 citations.
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Patent•
12 Mar 1985
TL;DR: In this paper, the luminescent materials can be used either as transducers for physical parameters or as means for processing information from other optical transducers, without requiring a change in the luminecence properties of said materials under the influence of the measured parameter.
Abstract: Methods, materials and devices for the remote measurement of physical variables with fiber optic systems use a single excitation light source for generating through the use of at least one luminescence converter, both a signal beam and a reference beam, and allow the transmission of both beams through a single fiber to a single photodetector, thus producing photo-electric signals the relative intensities of which are only minimally affected by changes of the intensity of the interrogating light beam, optical losses, or detector drift. In contrast to the prior art, the luminescent materials of this invention can be used either as transducers for physical parameters or as means for processing information from other optical transducers, without requiring a change in the luminescence properties of said materials under the influence of the measured parameter. Furthermore, the techniques and devices of this invention allow the use of luminescent materials for converting a measurand with a low coefficient of change under the action of the parameter being measured into a measurand with a large coefficient of change.
69 citations
TL;DR: Tunneling of photons in frustrated total internal reflection has been studied in the time domain with single-cycle femtosecond pulses and it is found that superluminal signal propagation is not possible in this case because of the inevitable diffractive spreading of the signal beam.
Abstract: Tunneling of photons in frustrated total internal reflection has been studied in the time domain with single-cycle femtosecond pulses. It is seen that both the phase and energy of the pulse travel faster than the speed of light in vacuum. Theoretical analysis of the experiments shows that the time-response function for electromagnetic waves propagating in the air gap is noncausal. However, it is found that superluminal signal propagation is not possible in this case because of the inevitable diffractive spreading of the signal beam.
67 citations
TL;DR: In this paper, the contrast and diffraction efficiency of dielectric holograms made from a diffuse signal beam was calculated and shown to be at least 64% with acceptable image contrast.
Abstract: The contrast and diffraction efficiency of a dielectric hologram made from a diffuse signal beam is calculated. Diffraction efficiency of 64% with acceptable image contrast is possible. Experimental results with holograms made by bleaching photographic emulsions are presented.
66 citations
TL;DR: A BBO-based chirped-pulse optical parametric amplifier employing an angularly dispersed signal beam to yield a full-octave gain bandwidth, sufficient for the direct amplification of sub-10-fs pulses and the suppression of parasitic second harmonic generation of the signal beam.
Abstract: We propose a BBO-based chirped-pulse optical parametric amplifier employing an angularly dispersed signal beam to yield a full-octave gain bandwidth, sufficient for the direct amplification of sub-10-fs pulses. Numerical simulations show that this power-scalable amplifier configuration has a small-signal gain of 10(7) at a pumping intensity of 45 GW/cm(2). The additional phase-matching flexibility compared to alternative configurations permits the suppression of parasitic second harmonic generation of the signal beam.
66 citations
TL;DR: From data, the optimum bias level and the ratio of the signal beam to the reference beam for recording interference patterns are determined, and the modulation transfer function of the film can also be determined.
Abstract: Various parameters of recording spatially modulated coherent light have been studied, with particular emphasis on the parameters related to constructing holograms These include the ratio of the reference beam's intensity to that of the signal beam, the offset angle, the film's transfer characteristic, and the recording wavelength Experimental results were obtained by recording interference patterns on highresolution film using the 6328-a line of the He-Ne laser The bias level of the interference pattern was varied so as to vary the operating point on the curve representing the film's amplitude transmittance vs exposure characteristics The percent modulation and the spatial frequency were also varied at each of the operating points Interference patterns were recorded, using the 4880-aand 5145-a lines from the argon laser From these data, the optimum bias level and the ratio of the signal beam to the reference beam for recording interference patterns are determined The modulation transfer function of the film can also be determined
65 citations