scholarly journals Lasers developed in the Institute of Atmospheric Optics of the SB RAS (a review)

2021 ◽  
Vol 9 (5) ◽  
pp. 417-429
Author(s):  
Anatolii Fedorov
Keyword(s):  
Peak Power ◽  
Radiation Power ◽  
Radiation Energy ◽  
Atmospheric Optics ◽  
Maximum Efficiency ◽  
Pulse Excitation ◽  
Nitrogen Laser ◽  
Transverse Excitation ◽  
Excimer Molecules ◽  
First Time

The results of research on the development of the first electric discharge lasers on active media N2, CO2, Cu, CuBr and excimer molecules at the Institute of Atmospheric Optics named after V. E. Zueva SB RAS are given. It created one of the world's first Cu-lasers with a pulse production of copper vapors due to the explosion of conductors and a transverse excitation discharge. For a copper laser, record specific generation parameters were obtained almost equal to the limit: radiation energy 2.4 J/l, peak power 120 MW/l with an efficiency of 0.16 %. For the CuBr laser operating in frequency mode, for the first time, an average radiation power of more than 100 W was obtained. In the dual pulse excitation mode, conditions were found that limit the growth of the efficiency of the CuBr laser. For him, a record efficiency of 2.7 % was obtained. For the first time, a nitrogen laser was developed with a maximum efficiency of 0.27 % with an energy of 0.8 mJ, a peak power of 160 kW. For the first time, a miniature XeCl laser with a longitudinal excitation discharge was developed, which worked both with and without buffer gases He, Ne and Ar.

scholarly journals Импульсный индукционный CO-=SUB=-2-=/SUB=--лазер с энергией излучения 1 J и высоким КПД с ВЧ возбуждением

2022 ◽  
Vol 130 (3) ◽  
pp. 400
Author(s):  
А.М. Ражев ◽  
Е.С. Каргапольцев ◽  
И.А. Трунов
Keyword(s):  
Laser Radiation ◽  
Co2 Laser ◽  
Radiation Energy ◽  
Maximum Efficiency ◽  
Cross Sectional ◽  
Energy Characteristics ◽  
Inductive Discharge ◽  
Cross Sectional Dimension ◽  
Pulsed Gas Discharge ◽  
First Time

An efficient pulsed gas-discharge inductive CO2-laser with a radiation energy of 1.05 J has been developed for the first time. In this case, the pulse duration of the laser radiation was about 10 msec. The maximum efficiency of 21.1% was obtained at a radiation energy of 340 mJ. RF current pulses propagated along the inductor conductor and, thus, an inductive discharge was formed to create an inverse population at the infrared (IR) transitions of CO2* molecules. The temporal and energy characteristics of the radiation of the inductive CO2-laser depending on the duration of the pump pulse are investigated. The spatial characteristics and spectrum of the radiation of the developed laser are estimated. The divergence of the laser radiation was 0.52 mrad. The cross-sectional dimension of the laser output beam was about 35 mm in diameter.

scholarly journals Новый люминофор ИК-диапазона на основе германата Sr-=SUB=-3-=/SUB=-La-=SUB=-2-=/SUB=-(Ge-=SUB=-3-=/SUB=-O-=SUB=-9-=/SUB=-)-=SUB=-2-=/SUB=- : Nd-=SUP=-3+-=/SUP=-, Ho-=SUP=-3+-=/SUP=-

2018 ◽  
Vol 60 (2) ◽  
pp. 358
Author(s):  
М.А. Мелкозерова ◽  
Я.В. Бакланова ◽  
О.А. Липина ◽  
А.Ю. Чуфаров ◽  
А.П. Тютюнник ◽  
...  
Keyword(s):  
Radiation Energy ◽  
Short Wave ◽  
Maximum Efficiency ◽  
Luminescence Spectra ◽  
Laser Radiation Energy ◽  
Precursor Method ◽  
Relaxation Energy ◽  
Infrared Luminescence ◽  
Concentration Dependences ◽  
First Time

AbstractCyclogermanate Sr_3La_2(Ge_3O_9)_2, isostructural to silicate Sr_3Er_2(Si_3O_9)_2, activated by neodymium and holmium is obtained for the first time by the precursor method. Ion Nd^3+ in the structure of Sr_3La_2(Ge_3O_9)_2 is a sensitizer of the infrared luminescence of Ho^3+. Excitation by radiation with a wavelength of 808 nm leads to a series of emission lines in the luminescence spectra of Sr_3La_2- x Nd_ x (Ge_3O_9)_2 : Ho^3+ in the short-wave and middle-IR ranges (1.0–3.4 μm). The highest intensity of lines at 2.1 and 2.7 μm, associated with the ^5 I _7 → ^5 I _8 and ^5 I _6 → ^5 I _7 transitions in the Ho^3+ ion, is found for compositions containing traces of holmium. Based on the analysis of the concentration dependences of the luminescence intensity, an optimal composition of the phosphor is determined, which ensures the maximum efficiency of conversion of laser radiation energy. The data obtained are interpreted in the assumption of cross-relaxation energy transfer from Nd^3+ to Ho^3+.

scholarly journals Нерезонансное обращение волнового фронта света на поверхности пленок GaN при большой мощности оптического возбуждения

2019 ◽  
Vol 53 (1) ◽  
pp. 26
Author(s):  
А.Н. Грузинцев ◽  
А.Н. Редькин
Keyword(s):  
Photon Energy ◽  
Signal Intensity ◽  
Room Temperature ◽  
Phase Conjugation ◽  
Charge Carriers ◽  
Nitrogen Laser ◽  
Free Charge ◽  
Laser Pumping ◽  
Infrared Spectral ◽  
First Time

AbstractThe possibility of the nonresonance phase conjugation of light in an excited semiconductor medium is shown theoretically and experimentally. In epitaxial GaN films pumped with a nitrogen laser at room temperature, the induced phase conjugation of light in the visible and infrared spectral regions is detected for the first time. The dependences of the phase-conjugation signal intensity on the photon energy and laser-pumping intensity are studied. An interpretation of the effect as a result of the absorption and refraction of light at laser-induced free charge carriers in the semiconductor medium is proposed.

MW peak-power UV inductive nitrogen laser

2020 ◽  
Vol 126 (6) ◽  
Author(s):  
A. M. Razhev ◽  
D. S. Churkin ◽  
R. A. Tkachenko
Keyword(s):  
Peak Power ◽  
Nitrogen Laser

scholarly journals Velocity shift of Mg ii and Al iii broad absorption lines in quasar SDSS J134444.33+315007.6

2020 ◽  
Vol 499 (1) ◽  
pp. L58-L61
Author(s):  
Wei-Jian Lu ◽  
Ying-Ru Lin
Keyword(s):  
Rest Frame ◽  
Background Radiation ◽  
Radiation Energy ◽  
Absorption Lines ◽  
Broad Absorption ◽  
Velocity Shift ◽  
System A ◽  
Variation Characteristics ◽  
Broad Absorption Lines ◽  
First Time

ABSTRACT We report, for the first time, a synchronized velocity shift of Mg ii and Al iii broad absorption lines (BALs) in quasar SDSS J134444.33+315007.6 (hereafter, J1344+3150). We found this quasar from a sample of 134 Mg ii BAL quasars with multi-epoch observations. This quasar contains three low-ionization BAL systems, the fastest of which at ${\sim} -17\, 000\, \rm km\, s^{-1}$ shows a kinematic shift of ${\sim} -1101$ and $\sim -1170\, \rm km\, s^{-1}$ in its Mg ii and Al iii ions, respectively, during a rest-frame time of about 3.21 yr. Meanwhile, this quasar also shows other various variation characteristics, including an obvious weakening in its continuum, a coordinated enhancement in multiple emission lines (Mg ii, C iii, and Al iii), and a coordinated enhancement in three Al iii absorption troughs. These variation characteristics convincingly indicate that the BAL outflows of J1344+3150 are under the influence from the background radiation energy. Thus, we infer that the velocity shift displayed in system A in the quasar J1344+3150 may indicate an actual line-of-sight acceleration of an outflow due to the radiation pressure from the central source.

Numerical Analysis of the Surface Aerodynamic Noise of the CRH3 High Speed Train

2014 ◽  
Vol 1044-1045 ◽  
pp. 643-649
Author(s):  
Ji Zhou Liu ◽  
Ren Xian Li ◽  
Peng Xiang Cui
Keyword(s):  
High Speed ◽  
Noise Source ◽  
Radiation Power ◽  
Spectral Characteristics ◽  
Radiation Energy ◽  
Simulation Method ◽  
Acoustic Power ◽  
Broadband Noise ◽  
Aerodynamic Noise ◽  
High Speed Train

For high speed trains running at 300km/h or more, the aerodynamic noise becomes the primary noise source. A good knowledge of the location, spectral characteristics and propagation behavior of the noise source and the corresponding methods to reduce the effect of the aerodynamic noise are of crucial necessity during the design process of the high speed train. Based on the Lighthill Analogy, the pressure fluctuation of air at the surface of the train is acquired by simulating the flow field of a CRH3 high speed train running at 200 km/h, 300 km/h, 400 km/h and 500km/h by means of large eddy simulation method. By Fourier transformation, the distribution and the spectral characteristics of the surface acoustic dipole sources are obtained. The analysis of the results shows that the aerodynamic noise of the high speed train is a broadband noise with a strong radiation power band from 50Hz to 1000Hz. The dipole acoustic power calculated by statistically averaged on train surface is found to be proportional to the sixth power of running speed of the high speed train. The first and second bogie, the inter-car gap, the air deflector of the power train and the train nose of the last wagon are the main noise sources that contain high radiation energy.

scholarly journals Излучательные характеристики мощных полупроводниковых лазеров (1060 нм) с узким мезаполосковым контактом на основе асимметричных гетероструктур AlGaAs/GaAs с широким волноводом

2020 ◽  
Vol 54 (4) ◽  
pp. 408
Author(s):  
И.С. Шашкин ◽  
А.Ю. Лешко ◽  
Д.Н. Николаев ◽  
В.В. Шамахов ◽  
Н.А. Рудова ◽  
...  
Keyword(s):  
Peak Power ◽  
Continuous Wave ◽  
Optical Power ◽  
Maximum Efficiency ◽  
Thermal Heating ◽  
Cw Operation ◽  
Power Profile ◽  
Low Efficiency ◽  
Narrow Stripe ◽  
A Current

Light characteristics of narrow-stripe lasers (5.5 m) based on asymmetric AlGaAs/GaAs heterostructures are studied. It was shown that the maximum optical power achieved under continuous-wave (CW) operation is limited by thermal heating and reaches 1695 mW at a current of 2350 mA at +25°C, and the maximum efficiency reaches 54.8 %. By reducing the operating temperature to -8°C, we were able to increase the maximum power to 2 W. A peak power of 2930 mW was obtained under pulsed operation (pulse width 240 ns, amplitude 4230 mA). It is shown there is a region of an “optical dip” in the power profile with a low-efficiency lasing of a train of pulses of sub-ns duration under pulsed operation.

scholarly journals Deep tissue optical imaging of upconverting nanoparticles enabled by exploiting higher intrinsic quantum yield through use of millisecond single pulse excitation with high peak power

Nanoscale ◽  
2013 ◽  
Vol 5 (20) ◽  
pp. 10034 ◽  
Author(s):  
Haichun Liu ◽  
Can T. Xu ◽  
Gökhan Dumlupinar ◽  
Ole B. Jensen ◽  
Peter E. Andersen ◽  
...  
Keyword(s):  
Quantum Yield ◽  
Optical Imaging ◽  
Peak Power ◽  
Single Pulse ◽  
High Peak ◽  
Pulse Excitation ◽  
High Peak Power ◽  
Deep Tissue

scholarly journals Analysis and Synthesis of Double Negative Dielectric Media Rectenna Systems for Ambient Microwave Energy Harvesting

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Apostolia Karampatea ◽  
Katherine Siakavara
Keyword(s):  
Frequency Band ◽  
Radiation Power ◽  
Radiation Energy ◽  
Input Voltage ◽  
Dipole Antenna ◽  
Double Negative ◽  
Mobile Telecommunication ◽  
Telecommunication System ◽  
Hybrid Schemes ◽  
Analysis And Synthesis

The concept of harvesting the ambient electromagnetic radiation energy, coming from public telecommunication wireless networks, has been recently subject of extensive research. Techniques proposed for this target use mainly antennas, as the grade gathering the radiation power. In this work, a method introducing the usage of specific dielectric structures with artificially negative electric permittivity and magnetic permeability (double negative media or DNG) in combination with wire dipole antenna sensors is proposed as an RF harvesting system. Theoretical study of the synthesized DNG medium’s performance and the distribution of the electromagnetic field in its interior is made, with the intention of finding the areas of maximum electric field intensity at which the antenna sensors would be positioned for maximum power scavenging. The received numerical results show that the synthesized schemes are capable of enhancing the energy gathering ability. Compared to the same antenna sensors positioned in free space, they ensure higher input voltage to the rectifier and also an increase of the available power about 10 dB. Moreover, they exhibit this performance for every direction of arrival of the incoming waves. The hybrid schemes DNG dipole antenna were designed for the Universal Mobile Telecommunication System (UMTS) frequency band, but the method is general and would be applied to any other frequency band and also with other antenna types.

scholarly journals Highly efficient 3-stage Doherty power amplifier using gate bias adaption

2010 ◽  
Vol 3 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Ildu Kim ◽  
Junghwan Moon ◽  
Jungjoon Kim ◽  
Seunghoon Jee ◽  
Junghwan Son ◽  
...  
Keyword(s):  
Output Power ◽  
Power Amplifier ◽  
Peak Power ◽  
Average Power ◽  
Maximum Efficiency ◽  
System Specification ◽  
Average Output ◽  
Highly Efficient ◽  
Doherty Power Amplifier ◽  
Power Region

This paper demonstrates a highly efficient 3-stage Doherty power amplifier (PA) employing an envelope tracking (ET) technique. The ‘3-stage’ Doherty PA is the most efficient architecture for a high peak-to-average power ratio (PAPR) signal among the various Doherty PAs. However, because of the lower peaking biases than those of the ‘N-way’ Doherty PA, the proper load modulation is hard to be achieved. To get proper modulation, the peaking PAs' gate biases have been adaptively controlled using the ET technique, and the peak power and maximum efficiency characteristic along the backed-off output power region is successfully achieved. By ADS and Matlab simulations, the overall behavior of the 3-stage Doherty PA employing the ET technique has been fully analyzed. To maximize the overall efficiency of the proposed 3-stage Doherty PA, the unit PA has been designed using class F−1 PA. For verification, the amplifier is implemented using 5 W and 10 W PEP LDMOSFETs for the 802.16e mobile world interoperability for microwave access (WiMAX) at 1 GHz with a 8.5 dB PAPR. The measured drain efficiency of the proposed 3-stage Doherty PA is 55.5% at an average output power of 37 dBm, which is a 7.54 dB backed-off output power. The digital feedback predistortion (DFBPD) algorithm has been used to linearize the proposed PA considering the ET technique. After linearization, the −33.15 dB of relative constellation error (RCE) performance is achieved, satisfying the system specification. These results show that the 3-stage Doherty employing the ET technique and saturated PA is the most suitable PA for the highly efficient and linear transmitter.

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