scholarly journals Cavity-dumped nanosecond Cr:LiSAF laser in the 985–1030 nm region for versatile seeding of Yb-based amplifiers

2022 ◽  
Vol 128 (2) ◽  
Author(s):  
Umit Demirbas ◽  
Franz X. Kärtner ◽  
Mikhail Pergament
Keyword(s):  
Thin Film ◽  
Output Coupler ◽  
Peak Power ◽  
Low Cost ◽  
Electrical Signal ◽  
Time Dependent ◽  
Central Wavelength ◽  
Variable Time ◽  
Diode Pumped ◽  
Single Emitter

AbstractWe report nanosecond (ns) cavity-dumped operation of a low-cost diode-pumped Cr:LiSAF laser around 1000 nm. The system is pumped with one 1-W single-emitter multimode diode at 665 nm. A Pockell cell (PC) and thin-film-polarizer (TFP) combination placed inside the cavity chops up an adjustable portion of the intracavity power and creates a variable time-dependent output coupler. Via adjusting the length and magnitude of the electrical signal going into the PC, output pulses with pulsewidths in the 2.5–500 ns range and with peak power levels above 10 W are generated at repetition rates up to 100 kHz. The central wavelength of the pulses could be smoothly tuned in the 985–1030 nm region, and is only limited by the anti-reflection coating bandwidth of the current PC and TFP. This versatile nanosecond source with 100 nJ level energies could serve as an attractive low-cost seed source for Yb-based amplifiers, including the cryogenic Yb:YLF systems.

scholarly journals Diode-pumped 10 W femtosecond Yb:CALGO laser with high beam quality

2021 ◽  
Vol 9 ◽  
Author(s):  
Jinfang Yang ◽  
Zhaohua Wang ◽  
Jiajun Song ◽  
Renchong Lv ◽  
Xianzhi Wang ◽  
...  
Keyword(s):  
Peak Power ◽  
Optical Pulse ◽  
Continuous Wave ◽  
Beam Quality ◽  
Mode Locking ◽  
Optical Efficiency ◽  
Stable Mode ◽  
Central Wavelength ◽  
Semiconductor Saturable Absorber ◽  
Diode Pumped

Abstract We demonstrate a diode-pumped femtosecond Yb:CaGdAlO4 (Yb:CALGO) laser with a semiconductor saturable absorber mirror (SESAM) for stable mode-locking operation. A perfect beam profile is measured under 10 W output power with $M_{x}^{2}$  = 1.017 and $M_{y}^{2}$  = 1.016 in the horizontal and vertical directions, respectively. At the repetition rate of 71.66 MHz, the optical pulse duration is 247 fs and the pulse energy is 140 nJ at the central wavelength of 1041 nm, corresponding to a peak power of 0.56 MW. In addition, we also generate continuous wave (CW) power of more than 15 W with TEM00 mode, corresponding to an optical-to-optical efficiency of 44.1%.

scholarly journals Conjugated Polymer (MEH-PPV:MWCNTs) Organic Nanocomposite for Photodetector Application

2018 ◽  
Vol 15 (4) ◽  
pp. 441-448
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Film ◽  
Spin Coating ◽  
Conjugated Polymer ◽  
Low Cost ◽  
Volume Ratio ◽  
Time Dependent ◽  
Nanocomposite Thin Film ◽  
Coating Method ◽  
Doping Ratio ◽  
Higher Sensitivity

Fabrication of a photodetector consists of the conjugated polymer "MEH-PPV"- poly (2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenlenevinylene) and MEH-PPV:MWCNT nanocomposite thin film. The volume ratio investigated was 0.75:0.25. MEH-PPV was dissolved in chloroform solvent and doped with MWCNTs. The spin coating method was used to achieve a facile and low cost photodetector. The absorption spectrum decreases by adding the CNTs. The PL spectrum detected recombination curve results by doping the polymer with CNTs, and AFM measurement showed an increase of roughness average from (0.168 to 2.43nm) of "MEH-PPV" and "MEH-PPV:CNTs", respectively. The doping ratio 0.25, which has a higher photoresponsivity, was evaluated at 1.70 A/W and 2.14 A/W of the UV and Vis. wavelength range. Time-dependent photocurrent analysis showed that the higher sensitivity was 176.56 % at 350nm and 290.99% at 500 nm of the "MEH-PPV:MWCNTs" thin films, while I-V characteristics showed a rectifying behavior.

Transmission Electron Microscopy of oriented Co84Cr14Ta2 thin films for longitudinal magnetic recording

1991 ◽  
Vol 49 ◽  
pp. 756-757
Author(s):  
T. P. Nolan
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Cost ◽  
Low Noise ◽  
Information Storage ◽  
High Coercivity ◽  
Magnetic Alloy ◽  
Magnetic Media ◽  
Transmission Electron

Thin film magnetic media are being used as low cost, high density forms of information storage. The development of this technology requires the study, at the sub-micron level, of morphological, crystallographic, and magnetic properties, throughout the depth of the deposited films. As the microstructure becomes increasingly fine, widi grain sizes approaching 100Å, the unique characterization capabilities of transmission electron microscopy (TEM) have become indispensable to the analysis of such thin film magnetic media.Films were deposited at 225°C, on two NiP plated Al substrates, one polished, and one circumferentially textured with a mean roughness of 55Å. Three layers, a 750Å chromium underlayer, a 600Å layer of magnetic alloy of composition Co84Cr14Ta2, and a 300Å amorphous carbon overcoat were then sputter deposited using a dc magnetron system at a power of 1kW, in a chamber evacuated below 10-6 torr and filled to 12μm Ar pressure. The textured medium is presently used in industry owing to its high coercivity, Hc, and relatively low noise. One important feature is that the coercivity in the circumferential read/write direction is significandy higher than that in the radial direction.

The Significance of Tread Element Flexibility to Thin Film Wet Traction

1975 ◽  
Vol 3 (4) ◽  
pp. 215-234 ◽  
Author(s):  
A. L. Browne ◽  
D. Whicker ◽  
S. M. Rohde
Keyword(s):  
Thin Film ◽  
Time Dependent ◽  
Lateral Expansion ◽  
Wheel Slip ◽  
Fluid Films ◽  
Thin Fluid

Abstract An analysis is presented for the action of individual tire tread elements on polished sections of pavement covered by thin fluid films. Tread element flexibility, wheel slip, and time-dependent loading are incorporated. The effect of the lateral expansion of tread elements on groove closure is also studied.

scholarly journals Moving Pearl Vortices in Thin-Film Superconductors

2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Vladimir Kogan ◽  
Norio Nakagawa
Keyword(s):  
Magnetic Field ◽  
Thin Film ◽  
Time Dependent ◽  
Superconducting Thin Film ◽  
Self Energy ◽  
London Equation ◽  
The Magnetic Field

The magnetic field hz of a moving Pearl vortex in a superconducting thin-film in (x,y) plane is studied with the help of the time-dependent London equation. It is found that for a vortex at the origin moving in +x direction, hz(x,y) is suppressed in front of the vortex, x>0, and enhanced behind (x<0). The distribution asymmetry is proportional to the velocity and to the conductivity of normal quasiparticles. The vortex self-energy and the interaction of two moving vortices are evaluated.

scholarly journals Performance Improvement of ZnSnO Thin-Film Transistors with Low-Temperature Self-Combustion Reaction

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1099
Author(s):  
Ye-Ji Han ◽  
Se Hyeong Lee ◽  
So-Young Bak ◽  
Tae-Hee Han ◽  
Sangwoo Kim ◽  
...  
Keyword(s):  
Thin Film ◽  
Photoelectron Spectroscopy ◽  
Large Scale ◽  
Low Cost ◽  
Thermal Analyses ◽  
Thin Film Transistor ◽  
Sol Gel ◽  
Annealing Temperatures ◽  
Zinc Tin Oxide ◽  
Thermal Limitation

Conventional sol-gel solutions have received significant attention in thin-film transistor (TFT) manufacturing because of their advantages such as simple processing, large-scale applicability, and low cost. However, conventional sol-gel processed zinc tin oxide (ZTO) TFTs have a thermal limitation in that they require high annealing temperatures of more than 500 °C, which are incompatible with most flexible plastic substrates. In this study, to overcome the thermal limitation of conventional sol-gel processed ZTO TFTs, we demonstrated a ZTO TFT that was fabricated at low annealing temperatures of 350 °C using self-combustion. The optimized device exhibited satisfactory performance, with μsat of 4.72 cm2/V∙s, Vth of −1.28 V, SS of 0.86 V/decade, and ION/OFF of 1.70 × 106 at a low annealing temperature of 350 °C for one hour. To compare a conventional sol-gel processed ZTO TFT with the optimized device, thermogravimetric and differential thermal analyses (TG-DTA) and X-ray photoelectron spectroscopy (XPS) were implemented.

scholarly journals Comparison of solar power measurements in alpine areas using a mobile dual-axis tracking system

2019 ◽  
Vol 2 (S1) ◽  
Author(s):  
Jelenko Karpić ◽  
Ekanki Sharma ◽  
Tamer Khatib ◽  
Wilfried Elmenreich
Keyword(s):  
High Altitude ◽  
Peak Power ◽  
Power Plants ◽  
Low Cost ◽  
Elevation Angle ◽  
Test Site ◽  
Maximum Power ◽  
Maximum Power Point ◽  
Photovoltaic Power ◽  
Power Point

Abstract The rising demand for sustainable energy requires to identify the sites for photovoltaic systems with the best performance. This paper tackles the question of feasibility of photovoltaic power plants at high altitude. A direct comparison between an alpine and an urban area site is conducted in the south of Austria. Two low-cost automatic photovoltaic power measurement devices with dual-axis sun tracking and maximum power point tracking are deployed at two test sites. The system periodically performs a scan over the southern semihemisphere and executes maximum power point adjustment in order to assess the performance for a given direction. The gathered data shows a higher photovoltaic power yield in the higher altitude test site. Furthermore, the high altitude photovoltaic power as a function of azimuth and elevation angle appears to be not only higher but also more flat than in lower altitudes. This indicates a lower power loss in case of deviation from the optimal solar angles. The results show that even on low-cost hardware a difference in photovoltaic power can be observed, even though in this experiment it amounts to less than 5% increase of peak power in higher altitudes. However, the measured peak powers on the mountain are more stable and therefore closer to a constant level than the heavily fluctuating peak power values at the low altitude site. Additionally, a slight shift in optimal elevation angles between altitudes can be observed, as the optimum angle turns out to be lower on the high altitude site. This angle shift could be caused by snow reflections on the mountainous test site.

A HIGH-RESOLUTION 2D IMAGING LASER RADAR FOR OCCLUDED HARD TARGET VIEWING AND IDENTIFICATION

2008 ◽  
Vol 18 (02) ◽  
pp. 393-400 ◽  
Author(s):  
ROBERT J. GRASSO ◽  
JOHN C. WIKMAN ◽  
DAVID P. DROUIN ◽  
GEORGE F. DIPPEL ◽  
PAUL I. EGBERT
Keyword(s):  
High Resolution ◽  
Target Identification ◽  
Low Cost ◽  
System Size ◽  
Operating Conditions ◽  
Array Technology ◽  
Diode Pumped ◽  
Target Ranging ◽  
2D Imaging ◽  
Gated Imaging

BAE SYSTEMS has developed a Low Cost Targeting System (LCTS) consisting of a FLIR for target detection, laser-illuminated, gated imaging for target identification, laser rangefinder and designator, GPS positioning, and auto-tracking capability within a small compact system size. The system is based upon BAE Systems proven micro-bolometer passive LWIR camera coupled with Intevac's new EBAPS camera. A dual wavelength diode pumped laser provides eyesafe ranging and target illumination, as well as designation; a custom detector module senses the return pulse for target ranging and to set the range gates for the gated camera. Trials show that the current detectors offer complete extinction of signals outside of the gated range, thus, providing high resolution within the gated region. The images have shown high spatial resolution arising from the use of solid state focal plane array technology. Imagery has been collected in both the laboratory and the field to verify system performance during a variety of operating conditions.

A low cost and single source atmospheric pressure vapor phase epitaxy of ZnS for thin film photovoltaic applications

2018 ◽  
Vol 221 ◽  
pp. 216-219 ◽  
Author(s):  
Y. Yusoff ◽  
P. Chelvanathan ◽  
N. Kamaruddin ◽  
Md. Akhtaruzzaman ◽  
N. Amin
Keyword(s):  
Thin Film ◽  
Vapor Phase ◽  
Atmospheric Pressure ◽  
Low Cost ◽  
Vapor Phase Epitaxy ◽  
Single Source ◽  
Photovoltaic Applications
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