The main purpose of the bar code in the modern world is the unique identification of the product, service, or any of their
features, so personal and stationary barcode scanners so widely used.
One of the important parameters of bar code scanners is their reliability, accuracy of the barcode recognition, response
time and performance.
Nowadays, the most popular personal barcode scanners contain a mechanical part, which extremely impairs the
reliability indices. Group of SUAI engineers has proposed bar code scanner based on laser beam acoustic deflection
effect in crystals [RU patent No 156009 issued 4/16/2015]
Through the use of an acousto-optic deflector element in barcode scanner described by a group of engineers SUAI, it can
be implemented in the manual form factor, and the stationary form factor of a barcode scanner.
Being a wave electronic device, an acousto-optic element in the composition of the acousto-optic barcode scanner allows
you to clearly establish a mathematical link between the encoded function of the bar code with the accepted input
photodetector intensities function that allows you to speak about the great probability of a bar code clear definition.
This paper provides a description of the issued patent, the description of the principles of operation based on the
mathematical analysis, a description of the layout of the implemented scanner.
KEYWORDS: Signal processing, Bragg cells, Acousto-optics, Radio optics, Acoustics, Radio optics, Acousto-optics, Tunable filters, Diffraction, Spectroscopy, Mathematical modeling, Analytical research
The analysis of the spectra of the dynamic signals in optical range by techniques of acousto-optics at light diffraction on a traveling acoustic wave excited by a periodic sequence of radio pulses with a rectangular envelope and linear variation of the instantaneous frequency is considered. The expression of the spread function of the spectral device based on acousto-optical tunable filter that allows to investigate in detail the advantages of this optical spectrometer is obtained. Mathematical modeling of the spread functions for different values of speed of change of the instantaneous control frequency is performed. The results of experimental research are provided.
We consider the analysis of the spectra of the dynamic signal optical range by the methods of acousto-optics at light diffraction by a traveling acoustic wave excited by a periodic sequence of radio pulses with a rectangular envelope and a linear variation of the instantaneous frequency. The procedure of the linear approximation of the acousto-optic interaction is described. Acousto-optic interaction is thought of as a bilinear transformation of the spectral components, which are radio signal and optical radiation. It is shown that from the bilinear spectral transformation ensue relations, describing the spectral processing or radio or optical signal as a result of diffraction on grating structure formed by traveling acoustic wave. The problem of spectrum analysis of optical signals by optical spectral device based on acoustooptic tunable filter is considered separately. An expression allowing to investigating in detail the possibility of such an optical spectral device is obtained.
This research is conducted in order to design a spectral device for light sources power spectrum analysis. The spectral device should process radiation from sources, direct contact with radiation of which is either impossible or undesirable. Such sources include jet blast of an aircraft, optical radiation in metallurgy and textile industry. In proposed spectral device optical radiation is guided out of unfavorable environment via a piece of optical fiber with high dispersion. It is necessary for analysis to make samples of analyzed radiation as short pulses. Dispersion properties of such optical fiber cause spectral decomposition of input optical pulses. The faster time of group delay vary the stronger the spectral decomposition effect. This effect allows using optical fiber with high dispersion as a major element of proposed spectral device. Duration of sample must be much shorter than group delay time difference of a dispersive system. In the given frequency range this characteristic has to be linear. The frequency range is 400 … 500 THz for typical optical fiber. Using photonic-crystal fiber (PCF) gives much wider spectral range for analysis. In this paper we propose simulation of single pulse transmission through dispersive system with linear dispersion characteristic and quadratic-detected output responses accumulation. During simulation we propose studying influence of optical fiber dispersion characteristic angle on spectral measurement results. We also consider pulse duration and group delay time difference impact on output pulse shape and duration. Results show the most suitable dispersion characteristic that allow choosing the structure of PCF – major element of time-dispersion spectral analysis method and required number of samples for reliable assessment of measured spectrum.
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