Phase-modulated single-photon nonreciprocal transport and directional router in a waveguide-cavity-emitter system beyond the chiral coupling

We propose a potentially practical scheme for the controllable single-photon transport via waveguides which are coupled to a microcavity-emitter system. The microcavity-emitter system consists of a V-type three-level emitter and two or one single-mode microcavity. A driving field is used to drive a hyperfine transition between two upper excited states of the V-type three-level emitter. Beyond chiral coupling between waveguides and microcavity-emitter system, we show that the perfectly nonreciprocal single-photon transport in a single waveguide and the single-photon router with 100% routing probability in two waveguides can be achieved. Interesting enough, whether the nonreciprocal single-photon transport or the single-photon router can be switched periodically by adjusting the phase associated with microcavity-emitter coupling strength and the driving field. The complete physical explanation of the underlying mechanism is presented.

A Nonlinear Fingerprint-Level Radar Simulation Modeling Method for Specific Emitter Identification

With the development of information technology for modern military confrontations, radar emitter fingerprint identification has become a hot and difficult topic in the field of electronic warfare, especially in the field of electronic reconnaissance. Owing to the confidentiality of military systems, most of the existing studies use simulation data for radar emitter fingerprint identification experiments and analysis. However, most of the existing modeling methods focus on the mechanism analysis of the nonlinear fingerprint characteristics of a single independent component. Its main disadvantage is that it can only represent the nonlinear fingerprint characteristics of some components in the radar emitter system but cannot fully reflect the nonlinear fingerprint characteristics of the whole radar emitter system. In this paper, a nonlinear fingerprint-level radar simulation modeling method is proposed. In contrast to the previous single component modeling method, the systematic nonlinear characteristic modeling method of this model can provide individual radar signal data under different modulation modes and working parameters, and provide experimental conditions for data support and theoretical analysis of radar emitter fingerprint identification.

Modeling of self-excited stress measurement system

In the paper two types of numerical models of the self-excited acoustical system are presented. This new type of auto-oscillating system is used for stress change measurement in constructions and rock masses. The essence of the self-excited acoustical system is to use a vibration emitter and vibration receiver placed at a distance, which are coupled with a proper power amplifier, and which are operating in a closed loop with a positive feedback. This causes the excitation of the system. The change of the velocity of wave propagation, which is associated with the change of the resonance frequency in the system is caused by the deformation of the examined material. Stress changes manifest themselves in small but detectable variations of frequency. The first of the presented models was created on the basis of estimating the model parameters by identification of the sensor–conditioner–amplifier–emitter system. The second mathematical model was delivered from the force–charge equation of the piezoelectric transducers: the sensor and the emitter. The model of the loaded beam, which determined the response of any beam point to the force applied to any other beam point is also presented.

Experimental study of radiator, underfloor, ceiling and air heater systems heat emission performance in TUT nZEB test facility

This paper reports the results of different heat emitter system measurements, which were carried out at the nZEB test facility near Tallinn University of Technology in early 2018. Radiators, underfloor heating, air heaters and radiant ceiling panels are studied as coupled with different control schemes ranging from ON-OFF to PI-type control. The objective is to assess and quantify the control accuracy and thermal comfort parameters among different configurations. Scheduled heating dummies are used to simulate internal heat gains within the otherwise unoccupied test rooms. Along with outdoor temperature variation, the heating demand is therefore constantly changing and the control systems are continuously adjusting the heat output to maintain the desired indoor air temperatures. Control accuracy is then determined from the temperature deviations against this set value. Air stratification within the room is assessed with vertical temperature gradient calculations from measured air temperatures at different heights. The operative temperature at the point of expected occupancy is calculated from surrounding air and enclosing surface temperatures. The quantified results provide a comprehensive comparison between the different system configurations, enabling further energy simulations in related software packages since these parameters directly influence the energy usage within a system.

RBS Study of Multilayer Structure Material of Si/SiO2 Nano Films

An absorber-emitter system was fabricated using a multi-layer structure of amorphous silicon and silicon oxide thin films. The layers were deposited using RF magnetron sputtering system. The thin films were alternated in a periodic structure to form a one-dimensional photonic crystal. Each period in the crystal consisted of one layer of 57 nm thick silicon and a 100 nm thick silicon oxide layer. Several samples were prepared consisted on different periods (N= 1, 2, 3, 4, 5 and 10). Rutherford Backscattering Spectrometry technique (RBS) was used to verify the number of layers and their alternation, checking the thicknesses and determine the real stoichiometry in each layer of Si and SiOx.