Effect of hydrophobization of airfield coatings on the consumption of deicing reagents2

The issue of reducing costs for the maintenance of airfield coatings is particularly important nowadays due to the increase in the intensity of domestic air transportation. A significant part of the costs of the operational maintenance of airfields is spent on the purchase of deicing reagents (DIR) used to protect airfield pavements from icing. There is a possibility to reduce the required amount DIR by using of hydrophobizing impregnations (HPI) for cement concrete airfield pavements. The assumption about possibility to reduce costs for DIR by using HPI was proven by laboratory tests on specimens of cement concrete slabs. In the course of laboratory tests the process of airfield pavement icing and de-icing was modeled. According to the results of experimental studies it was determined that the consumption of DIR for cement concrete slabs specimens treated with HPI was reduced by 35% compared to similar specimens without HPI treatment. For the economic evaluation of cost reduction for the purchase of DIRs, the costs of applied DIRs used at civil airfields of the Russian Federation were analyzed, taking into account their location in different climatic zones. The assessment has revealed that the cost savings for the purchase of DIRs can be up to 29.1 %

Optical vortex propagation in few-mode rectangular polymer waveguides

We demonstrate that rectangular few-mode dielectric waveguides, fabricated with standard lithographic technique, can support on-chip propagation of optical vortices. We show that specific superpositions of waveguide eigenmodes form quasi-degenerate modes carrying light with high purity states of orbital angular momentum

Demonstration of optical vortex propagation in on-chip rectangular dielectric waveguides

Orbital angular momentum (OAM) of light provides an additional degree of freedom for multiplexing the data streams in optical communications, increasing further the channel capacity [1]. Applications of OAM for both classical data transmission [2] and quantum information [3] have been demonstrated. The key step towards robust, suitable for massive production, and cost-efficient OAM-assisted communications is the development of compact, on-chip integrable optical components. Summary form only given. Orbital angular momentum (OAM) of light provides an additional degree of freedom for multiplexing the data streams in optical communications, increasing further the channel capacity [1]. Applications of OAM for both classical data transmission [2] and quantum information [3] have been demonstrated. The key step towards robust, suitable for massive production, and cost-efficient OAM-assisted communications is the development of compact, on-chip integrable optical components.In this work we demonstrate propagation of vortex modes, carrying OAM, in rectangular dielectric waveguides, which can be produced with standard photolithography process. We show by numerical simulation that the specific superposition of waveguide eigenmodes form the quasi-degenerate modes carrying light with high purity states of OAM. Fig. 1(a-f) shows the amplitude and phase distributions of the dominant field component of quasi-TE vortex modes with topological charges ℓ = 1, 2 and 3, propagating in the few-mode waveguide with 10μmκ10μm PMMA core (n1 = 1.4794) and pure silica substrate (n2 = 1.444, n3 = 1). Numerical modelling has been performed using Matlab with full vector finite difference modesolver [4] for waveguide eigenmodes determination. We also demonstrate experimentally the propagation of the 1st order OAM mode in a polymer rectangular waveguide (4.5 μm × 4.1 μm core made of Ormosil with n1 = 1.50 at 1550 nm is deposited on silica substrate)