The paper proposes the new criterion of spatial resolution of an imaging system. This criterion considers shape and dimensions of a central peak and side lobes of a point spread function, standard deviation of noise. As a result, it helps to reach the optimal balance between the characteristics of a central peak, side lobes and noise. It differs from the widely known full width at half maximum and Sparrow criterion that mainly consider only characteristics of the central peak. There are discussed the digital filter optimal according to the proposed criterion and the limitations in maximization of spatial resolution of imaging systems.
We present rate equation model of a modified vertical surface-emitting laser with two optical-coupled active cavities (СС-VSCEL) and external optical channel. The model allows to determine all the relevant parameters – carrier densities, gains, and output powers – starting from two input parameters: the injection currents in each cavity taking into account the additional external photonic injection. The system of rate equations is solved for different operating regimes of the modified laser device. The results provided by the model shown that operating characteristics of CC-VCSEL greatly depend on the number of photons of the external injection.
This work focuses on the further development of the optical methods based on polarization detection to improve the reliability of the results of evaluation of structural changes in biological tissues. The paper presents an experimental study of tissues with pathological alterations to assess the capacity of differentiation of pathological conditions when using averaged local Mueller matrix elements. Experiments were carried out in direct scattering mode in histological samples of human epidermis. The practical significance of the results is the widespread application of the methodology for laser polarimetric analysis of structural changes in anisotropic tissues to identify and assess the degree of pathology in medical diagnosis of skin diseases.
Design of a fiber optic gyroscope FOG using a photosensitive line to scan interferograms is proposed. Shift periods depends mainly on the change of the phase of counter light waves propagating along the closed loop in opposite directions while rotating loop around an axis that is normal to its plane. Phase shift is proportional to the angular velocity Ω and the area of the circuit S which is bypassed by the counter-propagating waves. Proposed FOG design significantly reduces the impact of the following optical noise factors: zero drift, Rayleigh scattering, the Kerr effect, etc.
The given paper considers experimental methods and means of laser polarimetry that can be used for control of
polarization parameters of biotissues, in particular, in case of determination of the degree of pathological changes in
human skin. The scheme and operation of universal automated imaging polarimeter are considered. The results of
experimental research of Mueller matrices and corresponding polarization characteristics for thin cuts of human skin
with visualization by means of vector analysis are presented.
In this paper an influence of imperfections of polarizing elements imaging Muller-polarimeter on accuracy of measurement is investigated. The operating of polarimeter is based on three probing polarization method (). The optimal scheme of polarimeter was chosen and recommendations on a selection of its parameters were produced.