scholarly journals Review of the Yb3+:ScBO3 Laser Crystal Growth, Characterization, and Laser Applications

2021 ◽  
Vol 11 (22) ◽  
pp. 10879
Author(s):  
Dazhi Lu ◽  
Xiaoheng Li ◽  
Haohai Yu ◽  
Huaijin Zhang ◽  
Jiyang Wang
Keyword(s):  
Continuous Wave ◽  
High Energy ◽  
Output Energy ◽  
Energy Output ◽  
Laser Generation ◽  
Pulsed Lasers ◽  
Laser Applications ◽  
Practical Applications ◽  
Growth Characterization ◽  
Q Switching

Passive Q-switching is an effective approach for generating pulsed lasers, owing to its compact and additional modulation-free design. However, to compare favorably with active Q-switching and multi-stage amplification, the output energy needs to be enhanced for practical applications. Kramers Ytterbium ion (Yb3+)-doped borate crystals, with their excellent energy storage capacity, have been proven to be high-potential laser gain mediums for achieving pulsed lasers with moderate and high output energy using passive Q-switching technology. In this study, the growth, characterization, and laser generation of one Yb3+-doped borate crystal, the Yb3+:ScBO3 crystal, are systematically reviewed. The continuous-wave and passive Q-switching laser characteristics are presented in detail, and the self-pulsations derived from intrinsic ground-state reabsorption are also demonstrated. The specific characteristics and experiments confirm the potential of the Yb3+:ScBO3 crystal for future pulsed laser applications with moderate or even high energy output.

scholarly journals In-Band Pumped Continuous-Wave Lasers Based on Ho:KY(WO4)2 Crystal and Ho:KGdYbY(WO4)2 Epitaxial Layer

2020 ◽  
Vol 11 (4) ◽  
pp. 264-271
Author(s):  
O. P. Dernovich ◽  
N. V. Gusakovа ◽  
V. E. Kisel ◽  
A. V. Kravtsov ◽  
S. A. Guretsky ◽  
...  
Keyword(s):  
Single Crystal ◽  
Output Power ◽  
Epitaxial Layer ◽  
Continuous Wave ◽  
Maximum Output Power ◽  
Laser Generation ◽  
Maximum Output ◽  
Solid State Lasers ◽  
Practical Applications ◽  
Double Tungstate

2 μm lasers are in demand for a number of practical applications, such as environmental monitoring, remote sensing, medicine, material processing, and are also used as a pump sources for optical parametric generators. Crystals of double potassium tungstates doped with ions of rare-earth elements were shown to be promising materials both for  the  creation  of  classical  solid-state  lasers  and  waveguide  lasers. The aim of this work was to develop a tunable pump laser in the spectral region of 1.9 µm based on double tungstate crystals doped with thulium ions and to study the lasing characteristics of a Ho:KY(WO4)2 crystal and a Ho:KGdYbY(WO4)2 single-crystal epitaxial layer under in-band pumping.With a Ho(1at.%):KY(WO4)2  crystal, continuous wave low-threshold lasing with an output power of 85 mW with a slope efficiency of 54 % at 2074 nm was achieved. For the first time to our knowledge, continuous wave laser  generation  in  a  waveguide  configuration  is  realized  in  a  single-crystal  layer of potassium tungstate doped with holmium ions grown by liquid-phase epitaxy. The maximum output power at a wavelength of 2055 nm was 16.5 mW.

scholarly journals Production of Energy from Water Flow Output in Fish Tank

2020 ◽  
Vol 2 (1) ◽  
pp. 21-30
Author(s):  
Muniandy Sivasambu ◽  
Nik Aziz bin Nik Ali
Keyword(s):  
Renewable Energy ◽  
Water Flow ◽  
Flow Rate ◽  
Energy Demand ◽  
Water Flow Rate ◽  
High Energy ◽  
Output Energy ◽  
Energy Output ◽  
Severe Problem ◽  
Aquaculture Industry

Nowadays, the world is confronting the increasing energy demand, reduction of emissions and security of energy supply. The high energy demand leads to a severe problem, and we need to reduce the usage of non-renewable energy to avoid adverse climate change. Thus, renewable energy is an important role obtained from the natural environment and can be replenished naturally from those sources without environmental degradation. Water energy is one of the most promising renewable energy sources today, especially in the aquaculture industry. Hydropower played a vital role in producing large scale power and electricity. This study was set up to determine the electrical energy output depending on the different sizes and shapes of tanks. It is also to measure the water flow rate based on different size and shape tanks. Besides, the Pelton type of water turbine generator micro-hydroelectric DC 12V output was used in this experiment. Two types of tanks (rectangular and circular) with three different sizes (0.5 ton, 1.0 ton and 2.0 ton) were tested to measure high value of output energy (V) and flow rate (m3/s) by using clear water and wastewater. The result significantly shows that the circular tank had a higher water flow rate and output energy than the rectangular tank due to higher gravitational force, where the outlet placed in the middle and edge of the tank, respectively. The finding of this study benefits the aquaculture industry, where it introduced an alternative and cheaper method of reusing wastewater, reducing the cost maintenances and enhancing the profit of the business.

In situ TEM Studies of agglomeration of sub-nanometer Ru layers in Ru/C multilayers

1992 ◽  
Vol 50 (1) ◽  
pp. 256-257
Author(s):  
Tai D. Nguyen ◽  
Ronald Gronsky ◽  
Jeffrey B. Kortright
Keyword(s):  
Layered Structure ◽  
Driving Force ◽  
High Energy ◽  
Superior Performance ◽  
In Situ Tem ◽  
Rayleigh Instability ◽  
Practical Applications ◽  
Transmission Electron ◽  
Diffraction Patterns

Nanometer period Ru/C multilayers are one of the prime candidates for normal incident reflecting mirrors at wavelengths < 10 nm. Superior performance, which requires uniform layers and smooth interfaces, and high stability of the layered structure under thermal loadings are some of the demands in practical applications. Previous studies however show that the Ru layers in the 2 nm period Ru/C multilayer agglomerate upon moderate annealing, and the layered structure is no longer retained. This agglomeration and crystallization of the Ru layers upon annealing to form almost spherical crystallites is a result of the reduction of surface or interfacial energy from die amorphous high energy non-equilibrium state of the as-prepared sample dirough diffusive arrangements of the atoms. Proposed models for mechanism of thin film agglomeration include one analogous to Rayleigh instability, and grain boundary grooving in polycrystalline films. These models however are not necessarily appropriate to explain for the agglomeration in the sub-nanometer amorphous Ru layers in Ru/C multilayers. The Ru-C phase diagram shows a wide miscible gap, which indicates the preference of phase separation between these two materials and provides an additional driving force for agglomeration. In this paper, we study the evolution of the microstructures and layered structure via in-situ Transmission Electron Microscopy (TEM), and attempt to determine the order of occurence of agglomeration and crystallization in the Ru layers by observing the diffraction patterns.

scholarly journals Celery-derived porous carbon materials for superior performance supercapacitor

2021 ◽  
Author(s):  
Sirui Liu ◽  
Ya ping Xu ◽  
Jinggao Wu ◽  
Jing Huang
Keyword(s):  
Porous Carbon ◽  
Carbon Materials ◽  
High Energy ◽  
Cycle Life ◽  
Superior Performance ◽  
Energy Output ◽  
Next Generation ◽  
Porous Carbon Materials ◽  
Long Cycle Life ◽  
Sustainable Materials

Supercapacitors are of paramount importance for next-generation applications, demonstrating high energy output, an ultra-long cycle life and utilizing green and sustainable materials. Herein, we utilize celery, a common biomass from...

scholarly journals A Passively Q-Switched Holmium-Doped Fiber Laser with Graphene Oxide at 2058 nm

2021 ◽  
Vol 11 (1) ◽  
pp. 407
Author(s):  
Jinho Lee ◽  
Ju Han Lee
Keyword(s):  
Graphene Oxide ◽  
Pump Power ◽  
Fiber Laser ◽  
Ring Resonator ◽  
Continuous Wave ◽  
Optical Power ◽  
Polished Surface ◽  
Fiber Ring ◽  
Q Switching ◽  
Side Polished Fiber

This study reports a Q-switching-based, 2058-nm holmium (Ho) fiber laser incorporating a saturable absorber (SA) based on graphene oxide (GO). The SA was prepared with a side-polished fiber, while GO particles were deposited onto the fiber-polished surface to realize an all-fiber SA. A continuous-wave thulium-doped all-fiber laser, which was configured with a master-oscillator power-amplifier (MOPA) structure, was constructed as a pumping source. By inserting the fabricated SA into an all-fiber ring resonator based on 1-m length of Ho-doped fiber, Q-switched pulses could readily be obtained at a wavelength of 2058 nm. The pulse width was observed to vary from 2.01 to 1.56 μs as the pump power was adjusted from ~759 to 1072 mW, while the repetition rate was tunable from 45.56 to 56.12 kHz. The maximum values of average optical power and pulse energy were measured as ~11.61 mW and 207.05 nJ, respectively, at a ~1072 mW pump power.

Medical Cyclotrons

2009 ◽  
Vol 02 (01) ◽  
pp. 133-156 ◽  
Author(s):  
D. L. Friesel ◽  
T. A. Antaya
Keyword(s):  
Cancer Therapy ◽  
Scientific Research ◽  
High Energy ◽  
Industrial Applications ◽  
Medical Applications ◽  
Particle Accelerators ◽  
Radioisotope Production ◽  
Practical Applications ◽  
Medical Radioisotope ◽  
High Energy Particles

Particle accelerators were initially developed to address specific scientific research goals, yet they were used for practical applications, particularly medical applications, within a few years of their invention. The cyclotron's potential for producing beams for cancer therapy and medical radioisotope production was realized with the early Lawrence cyclotrons and has continued with their more technically advanced successors — synchrocyclotrons, sector-focused cyclotrons and superconducting cyclotrons. While a variety of other accelerator technologies were developed to achieve today's high energy particles, this article will chronicle the development of one type of accelerator — the cyclotron, and its medical applications. These medical and industrial applications eventually led to the commercial manufacture of both small and large cyclotrons and facilities specifically designed for applications other than scientific research.

scholarly journals A Novel Method for Breath Detection via Stepped-Frequency Continuous Wave Ultra-Wideband (SFCW UWB) Radars Based on Operational Bandwidth Segmentation

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3873 ◽  
Author(s):  
Hao Lv ◽  
Teng Jiao ◽  
Yang Zhang ◽  
Fulai Liang ◽  
Fugui Qi ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Doppler Radar ◽  
Ultra Wideband ◽  
Time Dimension ◽  
Processing Scheme ◽  
Practical Applications ◽  
Uwb Radar ◽  
Operational Frequency ◽  
Stepped Frequency ◽  
Breath Detection

Human being detection via ultra-wideband (UWB) radars has shown great prospects in many areas, such as biomedicine, military operation, public security, emergency rescue, and so on. When a person stays stationary, the main feature that separates him/her from surroundings is the movement of chest wall due to breath. There have been many algorithms developed for breath detection while using UWB radars. However, those algorithms were almost based on a basic scheme that focused on processing in the time dimension of UWB data. They did not utilize the benefits from the wide operational bandwidth of UWB radars to show potential superiority over those narrowband systems such as a continuous wave (CW) Doppler radar. In this paper, a breath detection method was proposed based on operational bandwidth segmentation. A basic theoretical model was firstly introduced, indicating that characteristics of breath signals contained in UWB echoes were consistent among the operational frequencies, while those of clutters were not. So, the method divided a set of UWB echo data into a number of subsets, each of which corresponded to a sub-band within the operational bandwidth of the UWB radar. Thus information about the operational frequency is provided for subsequent processing. With the aid of the information, a breath enhancement algorithm was developed mainly by averaging the segmented UWB data along the operational frequency. The algorithm’s performance was verified by data measured by a stepped-frequency CW (SFCW) UWB radar. The experimental results showed that the algorithm performed better than that without the segmentation. They also showed its feasibility for fast detection of breath based on a short duration of data. Moreover, the method’s potential for target identification and impulse-radio (IR) UWB radar was investigated. In summary, the method provides a new processing scheme for UWB radars when they are used for breath detection. With this scheme, the UWB radars have a benefit of greater flexibility in data processing over those narrowband radars, and thus will perform more effectively and efficiently in practical applications.

Analysis of data transmission technique based on pulsed laser

2012 ◽  
Vol 20 (1) ◽  
Author(s):  
T. Drozd ◽  
M. Zygmunt ◽  
P. Knysak ◽  
J. Wojtanowski
Keyword(s):  
Data Transmission ◽  
Continuous Wave ◽  
Pulsed Laser ◽  
Pulsed Lasers ◽  
Transmission Method ◽  
Transmission Systems ◽  
Laser Technology ◽  
Light Pulses ◽  
Transmission Technique ◽  
Transmission Speed

AbstractPulsed lasers are used mainly in lidar systems as sources of short and highly energetic light pulses. In data transmission systems continuous wave lasers are typically applied, however it is also possible to use pulsed lasers in such systems. Such approach seems to be especially reasonable for devices where a pulsed laser is applied anyway and executes another function (rangefinding). The article discusses a data transmission concept based on a pulsed laser technology. Advantages and limits of such a transmission method are described. Influence of individual transmission elements on the effective data transmission speed is analysed.

scholarly journals Deformation and failure in extreme regimes by high-energy pulsed lasers: A review

2017 ◽  
Vol 688 ◽  
pp. 429-458 ◽  
Author(s):  
Tane P. Remington ◽  
Bruce A. Remington ◽  
Eric N. Hahn ◽  
Marc A. Meyers
Keyword(s):  
High Energy ◽  
Pulsed Lasers ◽  
Deformation And Failure

Terahertz continuous-wave large-area traveling-wave photomixers on high-energy low-dose ion-implanted GaAs

2007 ◽  
Vol 90 (17) ◽  
pp. 171109 ◽  
Author(s):  
E. A. Michael ◽  
I. Cámara Mayorga ◽  
R. Güsten ◽  
A. Dewald ◽  
R. Schieder
Keyword(s):  
Traveling Wave ◽  
Low Dose ◽  
Continuous Wave ◽  
High Energy ◽  
Large Area ◽  
Ion Implanted
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