Fiber-optic transmission system of analyzed signal is considered to allow signals transmission from optical sources with either impossible or undesirable contact. Diffraction grating spectral device is chosen as investigation system. It should be noted that diffraction grating operates with transmitted light but not reflected. Influence of optical fiber consists in the distortion of wave front incident on the spectral device. Front distortion leads to a broadening of the device spread function in all diffraction orders, and as a consequence, to a deterioration in the device resolution. In this case, the complex spread function is a reaction of the device to the homogeneous plane monochromatic wave which clearly links the input-output of spectral device. Fiber-optic system influence is determined by introducing a fictitious transparency located directly in front of the diffraction grating.
Research of the effect the fiber-optic system has on the spread function of the diffraction grating spectral device is made in two ways. On one hand, mathematical model is proposed to describe the influence of a single-mode optical fiber to a spread function of the diffraction grating spectral device. We performed computer simulations of the analyzed signal transmission from the end of the optical fiber to the photodetector based on the proposed model. The calculations are performed for a single-mode optical fiber with a core diameter of 8 microns. On the other hand, experimental laboratory set up of the diffraction grating spectral device with a fiber optic transmission system is created. Theoretical calculations are compared with the experimental results.
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.
Energy spectrum estimation (i.e. evaluation) of optical radiation with the new spectrum analyzer is considered. This device is parallel resonant optical spectrum analyzer; its resolving system is a set of narrow–band optical resonators in the form of interference filters, each of which is equivalent to a system with lumped parameters. This allows us to consider only oscillations of the optical field in the form of scalar functions and adopt as a model of analyzed signal harmonized scalar random process. Photo detector operation and average of photocurrent using an integrator and integrating circuit is considered too. On the basis of the application prolate entire spheroidal wave function theory energy spectrum estimation by the integral of photocurrent is obtained. This estimation of the energy spectrum is consistent and asymptotically unbiased.