A method for generation of ultra-wideband electromagnetic pulses with a nanosecond length and a picosecond rise time has been proposed and studied. A horn antenna with a photoconductive switch irradiated by laser pulses has been used as an emitter. It is shown that the length of ultra-wideband electromagnetic pulses is determined by the antenna length and the semiconductor material and the rise front is determined by the front of laser pulses used to initiate a photoconductive switch. Typical pulse lengths of 1 ns with a rise front of up to 34 ps are reported.

A relatively simple fiber sensor system for high-power electromagnetic field measurements is presented. The system utilizes an all-dielectric fiber tip sensor head with CdTe electro optic (EO) crystal as an electric field transducer. The fiber sensor of small size converts electric field strength into modulation of light power. The rise time of the EO sensor is measured and evaluated theoretically. The system can be used for ultra-wideband high-power electric field measurements.

Field experiments were carried out to measure ultrawideband subnanosecond radiation pulses in the time domain, taking into account the influence of reflection from the Earth’s surface. The results of these experiments make it possible to prepare experiments in the free atmosphere on real paths of 10 km or more in length. A technical solution for the use of a single-channel ultrawideband emitter with a pulse duration of about 50 ps, which is optimal in terms of weight and size characteristics and lifting to heights of up to 1000 m, is substantiated. A specially designed measuring antenna in the form of a passive antenna array with high sensitivity is used as a receiving measuring channel.

The results of the first direct experiments on the passage of pulses of ultra-wideband radiation of subnanosecond duration in the Earth’s atmosphere at a distance of more than 10 km are presented. In contrast to the work calculated, the preservation of the amplitude–time shape of the pulses in the process of increasing the distance is shown. The establishment of this fact is of decisive importance in the practical application of ultra-wideband pulses in new technological developments.

The simple hybrid laser pulse-burst source is presented. The ability to manage pulse burst envelope shape and width was demonstrated. Intra-burst pulses duration and energies were 20 ps and 1.5 mJ, respectively.

A fiber master oscillator and a multi-pass system of bulk amplifiers for generating an arbitrary laser pulse shape with an energy of up to 1 J were demonstrated. External triggering made it possible to obtain a pulse on demand.

Field experiments have been carried out to measure ultra-wide-band subnanosecond radiation pulses in the time domain, taking into account the influence of reflection from the Earth's surface. Received results allow us to prepare experiments in a free atmosphere on real ranges of 10 kilometers or more in length. The optimal technical solution in terms of weight and size characteristics and elevation to heights up to 1000 meters is the using a single-channel ultra-wideband radiator with a pulse duration of about 50 ps and a specially designed measuring antenna in the form of a passive antenna array with high sensitivity.

A method for optical pump scheme optimization for a laser gain module with pulsed diode arrays for Nd:YAG rods (Ø10 × 130 mm & Ø10 × 160 mm) is presented. The goal is to maximize the small-signal gain of the laser gain module while maintaining a flat-top amplification profile. A possible way of the overall small-signal gain reduction due to amplified spontaneous emission is discussed and a method to deal with this phenomenon is given. As a result of optical pump scheme optimization, the gain module with the maximum pump power of 40 kW for 250 µs pulse duration at repetition rates of up to 25 Hz is created. The maximum small-signal gain G = 100 at 1.064 μm is achieved.

This paper presents single-mode waveguide Nd:YAG laser passively mode-locked with graphene saturable absorber. Fine tuning of intracavity losses provides the possibility not only to adjust the mode-locking stability but also to controllably switch between single- and dual-wavelength operation.

In this paper, we study a compact source of low-temperature cold atmospheric plasma based on a piezoelectric transformer used as a high-voltage source. This device can produce a direct piezo-discharge in the atmosphere, a classical dielectric barrier discharge, and a discharge in a noble gas flow. We have estimated the rotational and vibrational temperatures of the N2 ions and the electron temperature in the discharge from the emission spectra for different modes of source operation. When the source operated with loads of two types (metal and liquid loads), the electric field strength distribution near the discharge gap was measured with a probe operating on the basis of the Pockels effect. The possibility of application of this device for electromagnetic field impact on biological objects and plasma-activated media is discussed.

It is shown that direct measurements of the gain of weak signals of an active element irradiated by a probe laser can give a result much lower than that measured by the lasing threshold. A possible cause of such disagreement is discussed.

We report a new solid-state waveguide laser generating picosecond pulses with a GHZ, repetition rate, based on the use of graphene as a saturable absorber. Lasing at the main transverse mode is provided by the geometry of a cylindrical waveguide formed in the active crystal volume by the method of direct writing with a femtosecond laser beam. Fine tuning of the intracavity interferometer formed between the active medium and output mirror makes it possible to control the spectral-temporal parameters of output radiation and to smoothly tune the repetition rate of pulses having a duration of less than 20 ps. In particular, the possibility of dual-wavelength generation in the regime of continuous passive mode locking using a single saturable absorber based on graphene is demonstrated. By amplifying laser output radiation in the ytterbium fibre amplifier, an average output power of 539 mW is obtained.

The scheme generating UV pulses with a duration 15 ps and output energy up to 11.5 mJ is implemented in the system consisting of a picosecond Nd3+ : YAG laser with multistage nonlinearoptical conversion of fundamental frequency radiation into radiation with a wavelength 193 nm followed by an excimer ArF amplifier. The temporal characteristics and the contrast of the amplified pulses are measured.

The results of experimental investigations to measure the parameters of ultrashort electromagnetic pulses with a length of the order of 200 psec are considered. The investigations were made using an electrooptical electrical field strength converter based on a DAST crystal. The electromagnetic pulses were recorded using an IPPL-L measuring transducer. The data obtained are compared. It is established that the form of the output signals of both sensors is identical.

A photoemission source of directional pulsed wideband electromagnetic radiation in the microwave region is developed, and the time profile of the generated pulse is investigated. The source is a vacuum photodiode of a parabolic shape in which a Cherenkov radiation pulse is formed by an electron current wave excited by an incident laser pulse and propagating along the surface of the anode mesh with a phase velocity higher than the speed of light.

Results of numerical simulation of flat laser driven UWB microwave pulse generator using PIC code KARAT are presented. Calculation results compared with analytical estimations.

An electro-optical system is developed for measuring low field strengths (100 V cm −1 ) of ultra-wideband electromagnetic pulses using the DAST crystal. The electric field strength is measured and the spectral composition is calculated for the radiation of the experimental ultra-wideband electromagnetic pulse oscillator.

Powerful picosecond UV pulses at a wavelength of 193nm are produced using a Nd:YAG laser radiating at a wavelength of 193nm with subsequent nonlinear transformations of the radiation and amplification in an excimer gain medium to an energy of 10 mJ.