Sensitivity of prismatic integrated optical sensors under nearly critical conditions

The sensitivity of integrated optical sensors based on prismatic excitation of planar waveguides is analyzed. It is shown that the sensitivity peak is attained when the waveguide modes are excited under nearly critical conditions.     

Reconstruction of parameters of an adlayer on the surface of a channel optical waveguide

A simple solution of an inverse problem of reconstruction of thickness, permittivity and surface coverage of an adlayer disposed on the surface of a channel optical waveguide is proposed and substantiated theoretically. It is shown that the reconstruction errors for the parameters of the adlayer can be minimized by a choice of the channel waveguide parameters. The application of the procedure to biochemical sensors is considered.     

Negative Results in Form-Preserving Approximation of Higher Order

It is proved that for q-convex polynomial approximations, where $q \geqslant 4$ , inequalities of Jackson type are not valid even with a constant depending on the approximated function.     

Effect of fine crystalline structure on coercive force of e lectrodeposite d iron films

Iron films 1000 Å thick deposited on sheet copper at pH = 5 at current densities of 0.1–4 A /dm² were investigated. There is a symbatic relationship between H_c and the microstresses.Translated from Izvestiya VUZ. Fizika, No. 12, pp. 14–18, December, 1971.     

Influence of conditions of end fixing on the stability of longitudinally compressed multilayer conical shells

Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Prikladnaya Mekhanika, Vol. 24, No. 4, pp. 37–41, April, 1988.     

Generation of compound non-gaussian random processes with a given correlation function

A compound representation of random processes is considered. Each independent component of such a process is considered as the solution of the proper stochastic differential equation (SDE). This guarantees that the process obtained is stationary and ergodic. The analytical expressions are developed for nonlinear coefficients of the generating SDE. Theoretical results are compared with numerical simulation.     

Scattering of surface magnetic polaritons rom order-parameter fluctuations near second-order magnetic phase transitions

A study is reported of the scattering of surface magnetic polaritons in the vicinity of second-order spin-reorientational phase transitions, which is caused by spatial fluctuations of the order parameter. A four-sublattice antiferromagnet α-Fe₂O₃ is used as an example to derive expressions for the vacuum-scattered radiation near exchange magnetic-vibration frequencies. The scattering of surface magnetic polaritons is shown to be resonantly enhanced in characteristic regions of their spectrum. Estimates made for α-Fe₂O₃ indicate a possibility of experimental observation of surface magnetic-polariton scattering from fluctuations of the refractive index near second-order spin-reorientational phase transitions.     

Domain structure in an ultrathin ferromagnetic film: Three-parameter model

A stripe domain structure (DS) was studied in an ultrathin ferromagnetic film under an in-plane magnetic field. The basic structure parameters (the amplitude and period of the DS, the thickness of domain walls) were determined within a unified variational approach, and transitions from the DS state to a homogeneous canted and a homogeneous planar phase were studied.