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The author correctly synchronizes historical and religious Chronicles of the Ancient World based on a short chronology and linking events to unique celestial phenomena reflected in the annals and Scriptures. The author believes that discrepancies in dates,geographical localities and ethnic origin of historical and religious figures are due to erroneous traditional chronology and historical geography, as well as the deliberate adaptation of phenomena and events to an established paradigm. In addition, differences in religious traditions and facts of real history are caused by ignorance and fanaticism of adherents certain religions

Various methods for limiting the plasma volume made it possible to produce a continuous point-like high-temperature terahertz discharge at the Novosibirsk free-electron laser (NovoFEL). When a krypton-nitrogen jet was injected into the focus of the NovoFEL radiation, as compressed as possible and having an average power of about 200 W, a spherical plasma with a diameter of 1 mm, temperature of 4–4.5 eV (46 000–52 000 K), and density of 3.5 × 1017 cm−3 was obtained. The ion composition of the plasma is represented mainly by triply and doubly ionized krypton atoms (Kr IV and Kr III). The absolute stability of the plasma, which tends to self-oscillate, is achieved through the use of a special negative optical feedback.

This work demonstrates the possibility of switching the phase of optical free induction decay (FID) in time-domain experiments. This possibility arises in experiments with paramagnetic molecules (free radicals) in a magnetic field. Changing the direction of the magnetic field alters the direction of rotation of the FID polarization plane and inverts the phase of one of the components of FID. This effect will be useful for heterodyne detection of the optical FID of the free radicals in the terahertz region.

Free electron lasers (FELs) are unique sources of electromagnetic radiation with tunable wavelength. A high-power FEL has been created at the G. I.Budker Institute for Nuclear Physics. Its radiation frequency can be tuned over a wide range in the terahertz and infrared spectral ranges. As the source of electron bunches, this FEL uses a multi-turn energy-recovery linac, which has five straight sections. Three sections are used for three FELs which operate in different wavelength ranges (90–240 μm for the first, 37–80 μm for the second, and 5–20 μm for the third ones). The first and the second FELs were commissioned in 2003 and 2009, respectively. They are used for various applied and research problems now. The third FEL is installed on the last, forth accelerator loop, in which the electron energy is the maximum. It comprises three undulator sections and a 40 m optical cavity. The first lasing of this FEL was obtained in the summer of 2015. The radiation wavelength was 9 μm and the average power was about 100 W. The design power is 1 kW at a pulse repetition rate of 3.75 MHz. Radiation of the third FEL will be delivered to user stations from the protected hall in the near future. The third FEL commissioning results are presented and the current status of the first and second FELs as well as their future development prospects are described.

This paper presents a review of studies of the photoelectric properties of PbSnTe:In films obtained by molecular beam epitaxy and photosensitive structures in the far infrared and submillimeter ranges based on these films. The parameters of photodetector arrays of this type and detectors based on doped semiconductors and superconductors are compared. One-dimensional (2×128 elements) and two-dimensional (128 × 128 elements) PbSnTe:In based arrays with a sensitivity threshold of ~22 μm and an operating temperature of T ≤ 16 K are implemented. Under background-free conditions, the noise equivalent power (NEP) was NEP ≤ 10−18 W/Hz0.5 at T = 7 K for a black body radiation source at TBB = 77 K. In the submillimeter range of the spectrum, sensitivity to laser radiation with a wavelength λ ≤ 205 μm and a value NEP ≤ 10−12 W/Hz0.5 was observed without optimization of the design of the photosensitive element and minimization of the measurement circuit noise. The directions of the development of PbSnTe:In based radiation detectors are considered..

New procedures for recording flame using the terahertz radiation of the Novosibirsk free electron laser (NFEL) are described that allow us to investigate the kinetics of nonstationary waves of combustion and detonation in a gas mixture. Schemes of experiments and the results from recording a propagating front of combustion produced by a hydrogen–oxygen mixture are presented. Experiments are performed in the 115 to 200 μm range of wavelengths. Investigations are conducted at the absorption lines of water and OH radical and with these lines tuned out. Recording in the 0.4 to 0.9 μm optical range of wavelengths is done simultaneously. Waves of combustion from a stoichiometric 2H2 +O2 mixture are investigated at the initial atmospheric pressure in a channel 40 mm in diameter. The measured velocities of the combustion wave lie in the range of 10 to 1500 m s–1.

Interactions of high-power terahertz radiation from the Novosibirsk free-electron laser at a wave-length of 130 µm in an atmospheric window with a model aerosol cloud with a known droplet size distribution function has been studied experimentally for the first time. The experimental data are compared with theoretical calculation results obtained from solution of the lidar equation for conditions of the experiment.

The chiral properties of an artificial anisotropic structure composed of microhelices are numerically simulated using the example of a sample developed by a team of authors from the Institute of Semiconductor Physics of the Russian Academy of Sciences. It is shown that this artificial structure can exhibit strong chiral properties in the THz range. Analytical expressions for the dielectric, magnetic, and chiral susceptibilities of the structure are derived on the condition of strong gyrotropy. The calculated values of the angle of the electromagnetic-wave polarization plane rotation and the circular dichroism are compared with the experimental results.

The development results for passive quasi-optical selective components based on planar regularly patterned metallized microstructures of subwavelength topology are described. The components include different frequency filters, polarization beam-splitters, metastructures, thin resonant absorbers, which are elaborated both for stand-alone applications and for integration with various metrological systems used in subTHz and THz measurements. The methods for electromagnetic simulation, technological implementation, and components characterization are discussed

Chiral metamaterials of the terahertz range are formed by means of rolling of strained nanofilms. Structural elements of these metamaterials are metal-semiconductor microhelices. Resonant optical activity of new metamaterials in the terahertz range is demonstrated. Arrays of model wire helices are formed and tested in the microwave range.

A simple analytical method for calculating open stable laser cavities suggested earlier by the author is used for calculating losses and for performing efficient optimisation of an open optical resonator of the Novosibirsk terahertz free- electron laser. The gain and cavity losses are measured at various wavelengths. Good agreement between theory and experiment is observed. Optimisation of useful losses is considered and a correct expression is derived for their calculations in lasers with uniform saturation of the active medium. Possible potential modernisation of the laser resonator is considered, which may provide greater than twice the output power.

It is shown by optical spectroscopy and He-Ne laser backscattering that the so-called Drummond light of calcium oxide (dazzling bright white light) is equilibrium and caused by the transformation of this material a at certain threshold temperature (2000 K) from an analog of ideal white body (in the optical range) with an emissivity of about 0.1 into an almost ideal black body with an emissivity close to 1. Previously, it was believed that the intensity of this light approximately coincides with that of black body at temperatures above 900 K and exceeds the latter at lower temperatures due to luminescence.

The interaction of radiation of the Novosibirsk Free Electron Laser (FEL) at a wavelength of 130 μm in the atmospheric transmission window with a model aerosol cloud having the known droplet size distribution function has been studied experimentally. The experimental findings are compared with theoretical calculations obtained from solution of the lidar equation for the conditions of the experiment.

An increase in the electrical conductivity is observed in the Pb1−x SnxTe:In/BaF2 films subjected to laser radiation with a wavelength λ=336.8 μm (the frequency of ∼0.9×1012 Hz) at the liquid-helium temperature; this increase cannot be accounted for by a heating of the sample. The observed photosignal-relaxation time does not exceed the RC time constant of the measurement circuit (this time constant amounts to fractions of seconds) and is much shorter than in the case of illumination within the fundamental absorption band of Pb1 − x SnxTe:In. The results obtained relate to an increase in the low-frequency permittivity ɛ as a result of excitation (by photons of the submillimeter region) of one or two transverse optical phonons in the center vicinity of the Brillouin zone at the branch responsible for the ferroelectric phase transition. This circumstance brings about an increase in the space-charge-limited injection current that flows from the contacts without a generation of free charge carriers in the bulk.

The problem of the coupling losses experienced by the EH11 fundamental waveguide mode is solved for a laser cavity formed by two mirrors and a hollow circular waveguide between them. The optimal waveguide laser cavity is defined as that with minimal internal losses in which the radiation propagates inside the waveguide in the form of the EH11 mode. An analysis is made of the characteristics of the use of such cavities in lasers with a wide wavelength-tuning range.

The problem of the coupling losses experienced by the main waveguide mode is solved for a laser cavity formed by two mirrors with a hollow rectangular or planar waveguide between them. The optimal configurations and mirror positions are found for waveguides with different ratios of the sides. Laser cavities supporting a wide range of wavelengths are considered.

One-pulse spectroscopy is used for the first time for a direct diagnostics of separate free-electron laser pulses. Full pulse coherency in a stabilized NovoFEL regime was demonstrated. Generation at different side-band modes in different pulses was observed when stabilizing detuning between electron and light pulses was decreased.

An rf (27.5 MHz) discharge was used for the first time to pump a cw DCN laser, which made it possible to reduce its noise below the 10-4 (0.01%) level. The parameters of the active medium and of the laser cavity were optimised. It was found that cw operation was possible at five wavelengths near 200 μm. A record output power from a laser with a cavity 2.5 m long, reached at the 189.95 μm wavelength, was 430 mW. In this laser the consumption of the expensive deuterated ethylene C2D4 was 20 times less than the consumption of the deuterated methane CD4 in the most powerful dc-pumped DCN laser.

An rf (27.5 MHz) discharge was used for the first time to pump a cw H2O laser emitting at λ = 118.6 μm. This made it possible to reduce the noise by more than two orders of magnitude compared with dc lasers. Optimisation of the active medium, by adding various gases (H2, He, Xe), and of the type and geometry of the laser cavity, was carried out. The unsaturated gain, the saturation intensity of the active medium, and the internal cavity losses were measured. The maximum output power of a laser was 48 mW when the cavity was 2.5 m long. The noise/signal ratio was less than 10-4 in the frequency range 0.01— 40 kHz.

A simple analytical technique, based on the Babinet principle, for calculating low diffraction losses of different kinds in stable resonators is described. The technique was verified by comparison with the known numerical and analytical calculations of the losses in specific diffraction problems.

In this paper Anomalous Extraordinary Transmission (ET) is reported for s-polarization of low loss doubly periodic subwavelength hole arrays patterned on polypropylene (PP) substrates by conventional contact photolithography at the so-called THz-gap (1-10 THz). The unexpected enhanced transmittance for s-polarization (i.e. without spoof plasmons) was previously numerically demonstrated in subwavelength slits arrays. However, subsequently no experimental work has been devoted to this unexpected Extraordinary Transmission neither in subwavelength slits nor in subwavelength holes. Here, numerical study and experimental results of the Anomalous ET and the symmetric and antisymmetric transmittance modes associated with the already well-known p-polarization ET are shown alongside a systematically analysis of the frequency peaks as a function of hole size for both incident polarizations. This work was supported by Spanish Government and E.U. Feder under contracts Consolider “Engineering Metamaterials” CSD2008-00066 and TEC2008-06871-C02-01.

Sideband instability was observed very clearly in the long-pulse regime of the Novosibirsk terahertz free electron laser (FEL) by a Bruker vacuum Fourier spectrometer IFS-66v. For positive frequency detuning, simultaneous generation of six sideband modes was observed. Mode competition and mode switching have been registered. Negative frequency detuning decreased the number of sideband modes and an single-mode generation with the narrowest classical spectrum has been obtained for sufficiently large detuning .

At the present time, the radiation of the main first harmonic of the Novosibirsk terahertz free electron laser (FEL) lies in the range of 120-230 mum with power level of up to 400 W. The radiation of second and third harmonics was experimentally found in the FEL. This high harmonic FEL radiation extends its spectral range by a factor of 3. Rather high second harmonic radiation unusual for typical FEL allows uninterrupted radiation in the range of 40-230 mum.

Using the pulses of terahertz free electron laser and ultra-fast Schottky diode detectors, we observed the coherent transients within a free induction decay of gaseous nitrogen dioxide NO2. The laser excited different sub-bands of rotation spectra of NO2 containing about 50–70 lines. The free induction signal continued more than 30 ns and consisted of many echo-like bursts duration about 0.2 ns. Unlike the similar effect observed previously for linear and symmetric top molecules, the sequence of echo bursts is not periodic. The values for delay of individual echo are stable, and the set of these delays can be considered as a “molecular fingerprint” in the time domain.

Optical free induction decay (FID) in the region of 60–75 cm−1 was detected using 120 ps pulses of free electron laser. Signals were detected in real time using ultra-fast Schottky diode detectors. The oscillations corresponding to the splitting of absorption lines in deuterated water vapor (Δf = 0.15 cm−1) and hydrogen bromide (Δf = 0.02 cm−1) were detected. At high optical density, we observed the oscillations arising from “top-hat” shape of absorption lines. Free induction decay signals could be detected in a single shot. This observation allowed obtaining a spectrum in one laser pulse, which facilitates studies of very fast processes.

We show that THz chiral metamaterials consisting of large regular arrays of metal–semiconductor microhelices can be manufactured from strained heterofilms by directional rolling. We also report the results of an experimental study of the electromagnetic properties of such arrays.

It was found xperimentally that xenon is an effective buffer gas for rf-pumped HCN, DCN, and H2O lasers. The greatest effect, which was an increase in the output power and of the efficiency by a factor of 5, was observed for the λ = 189.95 μm line of the DCN laser. In the case of HCN and H2O lasers, xenon increased the values of these parameters by 33%.