3D scanning coherent lidar demonstration using frequency modulated continuous wave

2018 ◽  
Author(s):  
Wei Lu ◽  
Zhiyong Lu ◽  
Yu Zhou ◽  
Jiangfen Sun ◽  
Qian Xu ◽  
...  
Keyword(s):  
Continuous Wave ◽  
3D Scanning ◽  
Coherent Lidar

Spatial averaging-effects on turbulence measured by a continuous-wave coherent lidar

2009 ◽  
Vol 18 (3) ◽  
pp. 281-287 ◽  
Author(s):  
Mikael Sjöholm ◽  
Torben Mikkelsen ◽  
Jakob Mann ◽  
Karen Enevoldsen ◽  
Michael Courtney
Keyword(s):  
Continuous Wave ◽  
Spatial Averaging ◽  
Coherent Lidar

Frequency-Modulated Continuous-Wave Coherent Lidar With Downlink Communications Capability

2020 ◽  
Vol 32 (11) ◽  
pp. 655-658
Author(s):  
Zhongyang Xu ◽  
Kai Chen ◽  
Xiuyuan Sun ◽  
Kelin Zhang ◽  
Yicheng Wang ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Coherent Lidar

Microstructures of Laser Processed Fe-Cr Surface Alloys

1981 ◽  
Vol 39 ◽  
pp. 328-329
Author(s):  
P. A. Molian ◽  
K. H. Khan ◽  
W. E. Wood
Keyword(s):  
Cooling Rate ◽  
Pure Iron ◽  
Continuous Wave ◽  
Laser Surface ◽  
Material Surface ◽  
Constitution Diagram ◽  
Incident Power ◽  
Surface Alloying ◽  
Laser Surface Alloying ◽  
Spot Diameter

In recent years, the effects of chromium on the transformation characteristics of pure iron and the structures produced thereby have been extensively studied as a function of cooling rate. In this paper, we present TEM observations made on specimens of Fe-10% Cr and Fe-20% Cr alloys produced through laser surface alloying process with an estimated cooling rate of 8.8 x 104°C/sec. These two chromium levels were selected in order to study their phase transformation characteristics which are dissimilar in the two cases as predicted by the constitution diagram. Pure iron (C<0.01%, Si<0.01%, Mn<0.01%, S=0.003%, P=0.008%) was electrodeposited with chromium to the thicknesses of 40 and 70μm and then vacuum degassed at 400°F to remove the hydrogen formed during electroplating. Laser surface alloying of chromium into the iron substrate was then performed employing a continuous wave CO2 laser operated at an incident power of 1200 watts. The laser beam, defocussed to a spot diameter of 0.25mm, scanned the material surface at a rate of 30mm/sec, (70 ipm).

1848: Revolix 70 Watt 2 Micron Continuous Wave Laser Vaporesection of the Prostate. Preliminary Results After a One Year Follow-Up

2007 ◽  
Vol 177 (4S) ◽  
pp. 614-614
Author(s):  
Thorsten Bach ◽  
Thomas R.W. Herrmann ◽  
Roman Ganzer ◽  
Andreas J. Gross
Keyword(s):  
Continuous Wave ◽  
Continuous Wave Laser ◽  
Preliminary Results ◽  
Wave Laser ◽  
One Year

Leitlinien zur peripheren Gefäßdiagnostik mit der direktionalen continuous-wave (CW) Doppler-Sonographie

Phlebologie ◽  
2000 ◽  
Vol 29 (05) ◽  
pp. 142-145
Author(s):  
T. Hertel ◽  
B. Kahle ◽  
H. G. Kluess ◽  
M. Marshall ◽  
E. Rabe ◽  
...  
Keyword(s):  
Continuous Wave

Investigating the Nonlinear Optical Response of Pepper Oil under Low Power Irradiation with Continuous Wave Visible Laser Beam

2020 ◽  
pp. 131-138
Keyword(s):  
Refractive Index ◽  
Nonlinear Refractive Index ◽  
Nonlinear Optical ◽  
Continuous Wave ◽  
Diffraction Integral ◽  
Visible Laser ◽  
Limiting Property ◽  
Kirchhoff Diffraction Integral ◽  
Theoretical Results ◽  
Good Agreement

The nonlinear optical properties of pepper oil are studied by diffraction ring patterns and Z-scan techniques with continuous wave beam from solid state laser at 473 nm wavelength. The nonlinear refractive index of the sample is calculated by both techniques. The sample show high nonlinear refractive index. Based on Fresnel-Kirchhoff diffraction integral, the far-field intensity distributions of ring patterns have been calculated. It is found that the experimental results are in good agreement with the theoretical results. Also the optical limiting property of pepper oil is reported. The results obtained in this study prove that the pepper oil has applications in nonlinear optical devices.

High Temperature n- and p-type Doped Microcrystalline Silicon Layers Grown by VHF PECVD Layer-by-Layer Deposition

2003 ◽  
Vol 762 ◽  
Author(s):  
A. Gordijn ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
High Temperatures ◽  
Continuous Wave ◽  
Hydrogen Plasma ◽  
Silicon Layer ◽  
Dark Conductivity ◽  
High Deposition Rate ◽  
Layer By Layer ◽  
Microcrystalline Silicon

AbstractDue to the high temperatures used for high deposition rate microcrystalline (μc-Si:H) and polycrystalline silicon, there is a need for compact and temperature-stable doped layers. In this study we report on films grown by the layer-by-layer method (LbL) using VHF PECVD. Growth of an amorphous silicon layer is alternated by a hydrogen plasma treatment. In LbL, the surface reactions are separated time-wise from the nucleation in the bulk. We observed that it is possible to incorporate dopant atoms in the layer, without disturbing the nucleation. Even at high substrate temperatures (up to 400°C) doped layers can be made microcrystalline. At these temperatures, in the continuous wave case, crystallinity is hindered, which is generally attributed to the out-diffusion of hydrogen from the surface and the presence of impurities (dopants).We observe that the parameter window for the treatment time for p-layers is smaller compared to n-layers. Moreover we observe that for high temperatures, the nucleation of p-layers is more adversely affected than for n-layers. Thin, doped layers have been structurally, optically and electrically characterized. The best n-layer made at 400°C, with a thickness of only 31 nm, had an activation energy of 0.056 eV and a dark conductivity of 2.7 S/cm, while the best p-layer made at 350°C, with a thickness of 29 nm, had an activation energy of 0.11 V and a dark conductivity of 0.1 S/cm. The suitability of these high temperature n-layers has been demonstrated in an n-i-p microcrystalline silicon solar cell with an unoptimized μc-Si:H i-layer deposited at 250°C and without buffer. The Voc of the cell is 0.48 V and the fill factor is 70 %.

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