In the industrial environment of position-sensitive detectors' usage, the laser source used for position measurement is co-existing with different kinds of light sources along with their reflections and back-scatters from various surfaces. These randomly arising illumination noises may fall on the detector surface in different geometrical orientations and produce different unwanted effects. In this paper, we attempt to describe, model and analyze these stray noises with respect to the operation of PSDs. We also study how the presence of the spurious sources modifies the behaviour of these detectors. The experimental results obtained by using PSDs and signal beams along with the spurious sources are presented. The experimental data are compared with the results from the proposed mathematical model graphically.
Solid state lasers emitting at very short wavelengths (>10nm) are very attractive for several applications in material proce3ssing and holography, but not yet demonstrated. Physical limitations prevent using classic laser schemes. We present a semi-empirical and rigorous demonstration of the feasability of a solid state x-ray laser and find some relations of the suggested scheme with EIT (Electro-Magnetic Induced Transparency) and Lasing Without Inversion (LWI).
We propose a modified Michelson's interferometer with some applications in dimensional metrology. The configuration of a Michelson's interferometer using corner cubes instead of pane mirrors is further modified in a rectangular parallelogram. A double prism is introduced in one of the branches of the device in order to obtain a precision of (lambda) /4 and an accuracy of +/- (lambda) /8. The same scheme can be applied to develop absolute portable gravimeters. We present an interferometer version enabling reducing the free fall dropping height less than 25 cm, which is half size of any available device of the same class. Another version of the same interferometer enables a theoretical doubling of the dropping rate and a reduced dropping length with an effective improvement of the measurement precision of g. This solution may lead to a portable absolute dynamic gravimeter. The paper discusses the mathematical model in terms of transfer function of 'g' and describes the modified Michelson's interferometer with a 'futuristic' solution for a dynamic portable absolute gravimeter.
We introduce some preliminary results of measurement on a simulated corneal surface. The possibility to devise a reliable mathematical model to simulate the corneal behavior in order to obtain target refraction (TR) is also discussed during and after Photo Therapeutic Keratectomy (PKT).
PulsESPI, combined with an innovative beam deliver device, may enable obtaining a very accurate control sensor to determine with improved accuracy some of the laser material processing parameters like the geometry of the keyhole and cutting kerf in real time.
Solid state lasers operating in the x-ray region are very attractive because of the potential high-energy developable. We present a possible solution to obtain high-energy pulses with suitable time duration from deformed crystals. DFB laser emission can be obtained in crystals using the anomalous transmission angle. Ohtsuki firstly proposed this solution. We discuss an alternative ring configuration and different methods of excitation from ultra short laser pulses to laser beams generated by cooled atom traps.
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