Formation and Its Mechanism of High-speed Micro-grooving on Metal Surface by Angled CW Laser Irradiation

Laser micro-grooving has excellent potential to improve the surface properties of metals. In this study, high-speed micro-grooving of the surfaces of mild steel SS400 and aluminum alloy A1050 was investigated using a single-mode continuous-wave fiber laser with an average power of 200 W. Experiments were conducted at laser beam scanning speeds of 1 to 6 m/s. The incident angle of the laser beam in the plane perpendicular to the scanning axis was varied from 0 to 60°. A relatively deep groove (approximately 30 µm in depth) and a high upheaval (10 µm in height) were formed along the scanning line at an incident angle of 45° on the SS400, whereas only shallow grooves were formed on A1050. The micro-groove formation mechanism was discussed on the basis of high-speed camera observation, groove shapes, and the thermophysical properties of the metal. Asymmetric molten metal flow and solidification around the keyhole are thought to play important roles in micro-groove formation. Although the laser irradiation conditions must be optimized according to the thermophysical properties of the material, angled laser irradiation has the potential to effectively form micro-grooves.

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Fundamental Study on Micro-grooving by High-speed Scanning of CW Laser

The Proceedings of Conference of Chugoku-Shikoku Branch ◽

10.1299/jsmecs.2019.57.1012 ◽

2019 ◽

Vol 2019.57 (0) ◽

pp. 1012

Author(s):

Chie KATAYAMA ◽

Kyo KITAGAWA ◽

Yasuhiro OKAMOTO ◽

Akira OKADA

Keyword(s):

High Speed ◽

Fundamental Study ◽

Cw Laser ◽

Micro Grooving

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Spatial Continuous Wave Laser and Spatiotemporal VCSEL for High-Speed Long Haul Optical Wireless Communication Channels

Journal of Optical Communications ◽

10.1515/joc-2019-0061 ◽

2019 ◽

Vol 0 (0) ◽

Author(s):

I. S. Amiri ◽

Ahmed Nabih Zaki Rashed ◽

Abd Elnaser A. Mohammed ◽

Ehab Salah El-Din ◽

P. Yupapin

Keyword(s):

Wireless Communication ◽

High Speed ◽

Continuous Wave ◽

Propagation Distance ◽

Q Factor ◽

Optical Wireless Communication ◽

Continuous Wave Laser ◽

Optical Wireless ◽

Cw Laser ◽

Improvement Ratio

AbstractThis study has presented spatial continuous wave laser and spatiotemporal vertical cavity surface emitting laser (VCSEL) for high speed long haul optical wireless communication channels. Possible data rates range from 40 Gb/s to 250 Gb/s over propagation distance ranges from 500 km to 2500 km. The optical wireless communication (OWC) system performance is tested through the measurement of maximum Q-factor, minimum bit error rate (BER) and signal to noise ratio (SNR). It is observed that spatiotemporal VCSEL has presented better performance than CW laser in the OWC system, especially for long haul transmission applications. It is observed that SNR improvement ratio ranges from 8.15 % to 19 % by using spatiotemporal VCSEL than CW laser for bit rate of 40 Gb/s over propagation distance ranges from 500 km to 2500 km. Max. Q-factor improvement ratio ranges from 4.62 % to 13.71 % by using spatiotemporal VCSEL than CW laser for data rate of 40 Gb/s over propagation distance ranges from 500 km to 2500 km. So it is clear that spatiotemporal VCSEL is more suitable for long haul OWC applications than other optical sources.

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Multiphoton upconversion process in Tm3+ doped ZBLAN glass by CW laser irradiation

Optics Communications ◽

10.1016/j.optcom.2009.06.067 ◽

2009 ◽

Vol 282 (21) ◽

pp. 4249-4251 ◽

Cited By ~ 8

Author(s):

Jianfu Li ◽

Xiaoli Wang ◽

Zhankui Jiang

Keyword(s):

Laser Irradiation ◽

Zblan Glass ◽

Cw Laser ◽

Upconversion Process

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Early Response of Mechanically Exposed Dental Pulps of Swine to Antibacterial-Hemostatic Agents or Diode Laser Irradiation

Journal of Clinical Pediatric Dentistry ◽

10.17796/jcpd.35.3.73621w8l447r3887 ◽

2011 ◽

Vol 35 (3) ◽

pp. 271-276 ◽

Cited By ~ 3

Author(s):

M Cannon ◽

C Wagner ◽

JZ Thobaben ◽

R Jurado ◽

D Solt

Keyword(s):

Laser Irradiation ◽

Diode Laser ◽

High Speed ◽

Early Response ◽

Treated Group ◽

Ferric Sulfate ◽

Surrounding Tissue ◽

Tissue Samples ◽

Treatment Groups ◽

Sus Scrofa Domestica

Objectives: The purpose of this study was to compare the effectiveness of an antibacterial and hemostatic agent to diode laser irradiation in the healing of mechanically exposed porcine pulps. Materials and Method: The experiment required three adult swine (Sus scrofa domestica, Yorkshire) with 36 teeth prepared with occlusal penetrations into the pulpal tissues. The preparations were performed under general anesthesia and the pulps were exposed using high speed instrumentation with rubber dam isolation and a disinfected field. Following instrumentation the coronal pulpal tissue was amputated and immediately treated with ferric sulfate and chlorhexidine semi-gel (12), diluted Buckley' formocresol solution (12) for 5 minutes or laser irradiation with a diode laser (12). After treatment, hemostasis was obtained and a ZOE base applied to the treated pulps (36). The pulpal bases were all covered with a RMGI (Fuji II LC). The tissue samples were collected at 4 weeks (28 days). Following fixation, the samples were de-mineralized, sectioned,stained and histologically graded with a scale of 0-4. Results: The treatment groups were statistically different with the Laser Treated Group demonstrating the least inflammation. Conclusion: Pulpotomy treatment with the KaVo Gentle Ray Diode Laser demonstrated significantly less inflammation than the other two pulpal therapy modalities. The ferric sulfate and chlorhexidine mixture demonstrated the greatest inflammation as histologically graded. Also, the histological sections of pulpotomized swine teeth treated with the ferric sulfate and chlorhexidine mixture presented with black pigmented areas in the pulp and surrounding tissue. The formocresol group (clinical standard) and the diode laser group did not present with the black precipitate.

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