Magnetic-field-controlled optical transmission in a system of metal diaphragms with apertures and a thin dielectric interlayer

A system comprising two metal diaphragms with holes and a thin dielectric interlayer exhibits magnetic-field-controlled optical transmission. This phenomenon can be used, in particular, for the creation of light modulators.     

Measuring intraocular pressure using semiconductor laser autodyne

The possibility of using a semiconductor laser autodyne to determine the motion characteristics of the fibrous tunic of the eye under the pneumopulse action has been studied. The required characteristics of motion were determined by spectral analysis of the autodyne signal. The results revealed a relationship between the parameters of motion of the sclera and the intraocular pressure measured using a contactless pneumotonometer.     

Photonic structures and their application for measuring material parameters

A computer simulation and an experimental study of the frequency dependences of the transmission coefficients of photonic crystals are carried out on the basis of microstrip lines with distortion in their periodicity in the form of change in the microstrip dimensions and the permittivity of a substrate of one of the alternate pieces of the microstrip line in the range of 0–20 GHz. Good quantitative agreement between the results of calculations and experimental data is obtained. It is shown that there is a possibility of using open microwave transmission lines, namely, microstrip photonic structures, to implement a method for measuring the parameters of material samples with the specified geometrical shape and a certain size that perform a function of nonuniformity in the photonic structure.     

A Microwave Autodyne Meter of Vibration Parameters

A microwave autodyne vibration meter based on a Gunn oscillator is described. The device consists of a remote sensor with a horn and a digital display unit. The oscillator head is a waveguide section with a channel cross section of 7.2 × 3.4 mm². The active element is a 3A728B diode placed in the gap of a rod holder. For the plane metal reflector under study, vibrations with a minimum amplitude of 400 m were recorded at a distance exceeding 20 m. The minimum detectable amplitudes of the object vibrations were 0.5 and 1.5 m at distances from the horn of the autodyne oscillator of 7 and 70 cm, respectively.     

Systems-Analysis Assessment of the Effectiveness of Measures for Decreasing the Proliferation Risk of Fissioning Materials

Approaches to nonproliferation analysis from the standpoint of the potential dange of fissioning materials are demonstrated for two problems: the proliferation risk in a long-time global strategy for growth of nuclear fuel cycle and the choice of an efficient strategy for the utilization of weapons and power plutonium in Russia.Comparing open and closed nuclear cycles with multiple recycling of plutonium in fast reactors according to the criterion of potential proliferation risk (exposure risk) shows that the present methodological approach does not confirm the idea that proliferation is of a greater danger in a closed cycle, which has become the foundation for long-time nuclear policy of the US.     

Acoustic pressure induced period-doubling bifurcations in tympanic membrane oscillations

We demonstrate the possibility of using a quantum-confined semiconductor structure laser operating in the autodyne regime for the investigation of the amplitude-frequency characteristics of the tympanic membrane (TM). Using such a laser, it is established that an increase in the acoustic pressure leads to the appearance of subharmonics in the spectrum of TM oscillations at frequencies equal to one-half and one-quarter of the exciting signal frequency, which is evidence for period-doubling bufurcations.     

Current-voltage characteristics of metal-oxide-oxide-metal structures with several regions of negative differential resistance

We have studied the current-voltage (I-U) characteristics of heterostructures of the metal-oxide-oxide-metal type formed in a pressure contact of aluminum and zinc electrodes covered by natural oxide layers. It is established that the I-U curves of such structures can exhibit several N-shaped regions of negative differential resistance at both positive and negative bias voltages. This phenomenon can be of interest in designing oscillators, amplifiers, and frequency converters for high-frequency range and should be taken into account in selecting their operation regimes.