Through-focus spot shaping with asymmetric pupil optimization for laser stealth dicing

2021 ◽  
Author(s):  
Akinori Ohkubo ◽  
Sungho Jang ◽  
Youngchul Kwon ◽  
Deoksuk Jang ◽  
Jungchul Lee
Keyword(s):  
Focus Spot

Research on enhancement algorithm for small-scale focus-spot detection

2021 ◽  
Author(s):  
Xiaoyan Liu ◽  
Deqiang Jiao ◽  
Xiangxin Shao ◽  
Xin Mu
Keyword(s):  
Small Scale ◽  
Spot Detection ◽  
Focus Spot ◽  
Enhancement Algorithm

Investigation of Kumakhov lenses focus spot

1994 ◽  
Author(s):  
Svetlana V. Nikitina ◽  
Nariman S. Ibraimov ◽  
G. A. Vartaniants ◽  
Andrey N. Nikitin ◽  
Lutz Spielberger ◽  
...  
Keyword(s):  
Focus Spot

A method for abstracting edge profile of continuous phase plate focus spot

2013 ◽  
Vol 25 (12) ◽  
pp. 3205-3209
Author(s):  
李强 Li Qiang ◽  
徐凯源 Xu Kaiyuan ◽  
刘昂 Liu Ang ◽  
何宇航 He Yuhang ◽  
高波 Gao Bo
Keyword(s):  
Continuous Phase ◽  
Phase Plate ◽  
Edge Profile ◽  
Focus Spot

A new extra-focus monochromator designed for high-performance VUV beamlines

2015 ◽  
Vol 22 (2) ◽  
pp. 328-335 ◽  
Author(s):  
Chaofan Xue ◽  
Yanqing Wu ◽  
Ying Zou ◽  
Lian Xue ◽  
Yong Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Vacuum Ultraviolet ◽  
Wide Energy Range ◽  
X Ray ◽  
Ultraviolet Range ◽  
Line Spacing ◽  
Wide Energy ◽  
Focus Spot ◽  
Grating Monochromator ◽  
Mechanical Compatibility

A new monochromator called an extra-focus constant-included-angle varied-line-spacing (VLS) cylindrical-grating monochromator (extra-focus CIA-VCGM) is described. This monochromator is based on the Hettrick–Underwood scheme where the plane VLS grating is replaced by a cylindrical one in order to zero the defocus at three reference photon energies in the vacuum-ultraviolet range. It has a simple mechanical structure and a fixed focus spot with high performance over a wide energy range. Furthermore, its mechanical compatibility with a standard VLS plane-grating monochromator allows convenient extension into the soft-X-ray range.

Transient Thermomechanical Simulation of Laser Hammering in Optoelectronic Package Manufacturing

2004 ◽  
Vol 127 (3) ◽  
pp. 299-305 ◽  
Author(s):  
Ben Ting ◽  
Vincent P. Manno
Keyword(s):  
Steady State ◽  
Transient Response ◽  
Laser Energy ◽  
Steady State Solution ◽  
Heat Fluxes ◽  
State Solution ◽  
Asymptotic State ◽  
Element Analysis ◽  
Finite Element Analysis Simulation ◽  
Focus Spot

Laser hammering (LH) is a process used in the manufacturing of butterfly optoelectronic packages to correct laser-to-fiber misalignment that occurs when the semiconductor lasers are welded in place. High-power, precisely positioned pulsed lasers are used in LH to induce deformation of the fiber support housing to, in turn, induce realignment. A thermomechanical modeling study of LH is reported in this paper, which focuses on the degree to which a steady-state model can predict the asymptotic state of a transient response subjected to a periodic laser excitation. A baseline, two-dimensional fiber mounting/ferrule geometry is employed in a finite element analysis simulation case study. Various laser wave forms are applied to focus spot location sizes of 50 and 200μm over a range of applied heat fluxes (10-1000W∕mm2). Effects of laser energy deposition location, as well as the use of multiple lasers, are also studied. The results show that the steady-state solution is in good agreement with the asymptotic transient response for horizontal fiber displacement and fiber temperature. The laser focus spot surface temperature predictions are also found to be in reasonable agreement. However, the vertical fiber displacement tends to be overpredicted by the steady-state solution, sometimes by as much as an order of magnitude. The causes, both physical and computational, of this disagreement are discussed.

FOCUSING CONTROL BASED ON SPPs-SCATTERING MODULATION

2010 ◽  
Vol 19 (04) ◽  
pp. 535-541 ◽  
Author(s):  
FENGHUAN HAO ◽  
RUI WANG ◽  
JIA WANG
Keyword(s):  
Metal Film ◽  
Design Method ◽  
Control Device ◽  
Constructive Interference ◽  
Propagation Length ◽  
Exit Surface ◽  
Different Types ◽  
Focus Spot ◽  
Simulation Results

We demonstrate a design method of focusing-control device, which consists of single metallic nano-slit surrounded with the grooves at the metal exit surface. According to the principle of the constructive interference, the grooves are positioned to scatter the SPPs to the radiation lights with desired phases. The role of SPPs in the focusing control is investigated, by applying the design method in the four different types of metal film. The simulation results indicate that the focusing effects are dependant on the types of metal film, the metal film which supports the SPPs with a long propagation length can form an apparent focus spot, and the reason is discussed.

Readout Power Dependence of Signal Distribution Observed in Fourier Plane of Focus Spot

2005 ◽  
Vol 44 (5B) ◽  
pp. 3350-3352 ◽  
Author(s):  
Takashi Nakano ◽  
Emi Mashimo ◽  
Takayuki Shima ◽  
Yuzo Yamakawa ◽  
Junji Tominaga
Keyword(s):  
Power Dependence ◽  
Fourier Plane ◽  
Signal Distribution ◽  
Focus Spot

scholarly journals Improvement of Alert System against Tampering and Theft in Surveillance Cameras

2019 ◽  
Vol 24 (2) ◽  
pp. 98
Author(s):  
Furat N . Tawfeeq
Keyword(s):  
Surveillance System ◽  
Digital Recording ◽  
Alert System ◽  
Digital Video Recorder ◽  
Signal Wire ◽  
Video Recorder ◽  
Surveillance Cameras ◽  
Focus Spot ◽  
Slow Motions ◽  
Fast And Slow Motions

Use of Surveillance cameras in houses and markets became common, that resulted to minimize theft and make it a difficult task because it let recording and viewing what is going around. The wide application of these cameras, pushed thieves to seek new ways for abolition of the surveillance system and digital recording of events, such as cutting the signal wire between the camera and Digital video recorder or changing the direction of the camera away from the focus spot or damaging the camera or steal the device which means the loss of the recorded media. This paper focuses on such abolitions and fixed it by suggesting a way to notify the administrator immediately and automatically by Email about any violation of the system using MATLAB, which allow fast action by the administrator to fix such tampering. The results show that selecting of threshold equal to two was fair in detecting motion and value of five, in case of changing the camera direction through testing of fast and slow motions. http://dx.doi.org/10.25130/tjps.24.2019.039  

scholarly journals Photonic Jet-Shaped Optical Fiber Tips versus Lensed Fibers

Photonics ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 373
Author(s):  
Djamila Bouaziz ◽  
Grégoire Chabrol ◽  
Assia Guessoum ◽  
Nacer-Eddine Demagh ◽  
Sylvain Lecler
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Single Mode ◽  
Spot Size ◽  
Base Diameter ◽  
Core Diameter ◽  
Focus Spot ◽  
Photonic Jet ◽  
Focus Spot Size ◽  
Focusing Properties

Shaped optical fiber tips have recently attracted a lot of interest for photonic jet light focusing due to their easy manipulation to scan a sample. However, lensed optical fibers are not new. This study analyzes how fiber tip parameters can be used to control focusing properties. Our study shows that the configurations to generate a photonic jet (PJ) can clearly be distinguished from more classical-lensed fibers focusing. PJ is a highly concentrated, propagative light beam, with a full width at half maximum (FWHM) that can be lower than the diffraction limit. According to the simulations, the PJs are obtained when light is coupled in the guide fundamental mode and when the base diameter of the microlens is close to the core diameter. For single mode fibers or fibers with a low number of modes, long tips with a relatively sharp shape achieve PJ with smaller widths. On the contrary, when the base diameter of the microlens is larger than the fiber core, the focus point tends to move away from the external surface of the fiber and has a larger width. In other words, the optical system (fiber/microlens) behaves in this case like a classical-lensed fiber with a larger focus spot size. The results of this study can be used as guidelines for the tailored fabrication of shaped optical fiber tips according to the targeted application.

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