Controlling of Microstructure Generation by Direct Holographic Etching of Semiconductor Substrates

ABSTRACTControlling of microstructure generation was investigated in laser etching of n-GaAs. For single-beam etching and holographic etching with high ratios of average spacing of holographic grating to average spacing of microstructures (Λh/Λr), ripple structures were fabricated. Especially in p-polarization, spatial fluctuation was greater than that in s-polarization. This might occur because phase distortion inherent in the laser beam cannot be eliminated by the p-polarization beam irradiation. For holographic etching with small Λh/Λr ratios, ripple structures were changed into grating structures because these grating structures might be generated in phase with holographic gratings.

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An application of reflective holographic gratings for measurement of cylindrical curvature

Journal of Physics Conference Series ◽

10.1088/1742-6596/2145/1/012054 ◽

2021 ◽

Vol 2145 (1) ◽

pp. 012054

Author(s):

Chanikan Inneam ◽

Keerayoot Srinuanjan ◽

Witoon Yindeesuk

Keyword(s):

Laser Beam ◽

Linear Relationship ◽

Diffraction Pattern ◽

Holographic Grating ◽

Holographic Gratings ◽

The Relationship

Abstract This paper presented an application of reflective holographic gratings for the measurement of cylindrical curvature. The surface of the fabricated holographic grating was coated with gold by the sputtering method, where it became a reflective holographic grating. The grating was attached to the surface of various radius cylindrical objects. The diffraction pattern produced by the bent grating with different radius was observed by illuminating a laser beam normal to the grating surface. The gratings constant were calculated from the observed diffraction pattern. The relationship between the grating constants and the radius of cylindrical objects was obtained. The grating constant and the reciprocal of the radius of cylindrical objects was a linear relationship, with the least R-square between 0.85-0.97. Moreover, the y-intercept of the relationship between the grating constants and the reciprocal radius was consistent with the grating constant of the non-bended grating. As the radius of the grating approach is infinite, the reciprocal of the radius approaches zero, which is a non-bend grating. We can apply this method to measure the radius of cylindrical objects.

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Effects of ultraviolet laser beam irradiation on rabbit cornea and lens.

Sangyo Igaku ◽

10.1539/joh1959.30.112 ◽

1988 ◽

Vol 30 (2) ◽

pp. 112-120 ◽

Cited By ~ 3

Author(s):

Sadafumi TAKISE ◽

Shun'ichi HORIGUCHI ◽

Ichiro KARAI ◽

Shinya MATSUMURA ◽

Makoto HARIMA ◽

...

Keyword(s):

Laser Beam ◽

Beam Irradiation ◽

Rabbit Cornea ◽

Ultraviolet Laser ◽

Laser Beam Irradiation

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Active Shock-tube-diaphragm Rupture with Laser Beam Irradiation

42nd AIAA Aerospace Sciences Meeting and Exhibit ◽

10.2514/6.2004-1352 ◽

2004 ◽

Author(s):

Toru Takahashi ◽

Keiko Watanabe ◽

Akihiro Sasoh ◽

Hiroyuki Torikai ◽

Qian-Suo Yang

Keyword(s):

Laser Beam ◽

Shock Tube ◽

Beam Irradiation ◽

Diaphragm Rupture ◽

Laser Beam Irradiation

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Fundamental plasma diagnostic study for guiding TIG arc phenomenon by laser beam irradiation

QUARTERLY JOURNAL OF THE JAPAN WELDING SOCIETY ◽

10.2207/qjjws.38.60 ◽

2020 ◽

Vol 38 (2) ◽

pp. 60-67

Author(s):

Hiroyuki OKUDA ◽

Kazufumi NOMURA ◽

Satoru ASAI ◽

Shohei IWATA ◽

Yasushi KITANI ◽

...

Keyword(s):

Laser Beam ◽

Diagnostic Study ◽

Plasma Diagnostic ◽

Beam Irradiation ◽

Laser Beam Irradiation

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Characterization of dissimilar aluminum-copper material joining by controlled dual laser beam

10.21203/rs.3.rs-980159/v1 ◽

2021 ◽

Author(s):

Joon Ho Cha ◽

Hae Woon Choi

Keyword(s):

Laser Beam ◽

Power Distribution ◽

Near Infrared ◽

Weld Zone ◽

Tensile Tests ◽

Bead Width ◽

Single Beam ◽

The Core ◽

Beam Laser ◽

Dual Laser

Abstract Laser technology has many advantages in welding for the manufacture of EV battery packs. Aluminum (Al) and copper (Cu) are welded using a dual laser beam, suggesting the optimum power distribution for the core and ring beams. Due to the very high reflectance of Cu and Al exposed to near-infrared lasers, the material absorbs a very small amount of energy. Compared to single beam laser welding, dual beam welding has significantly improved surface quality by controlling surface solidification. The study focused on the quality of weld surface beads, weld properties and tensile strength by varying the output ratio of the core beam to the ring beam. Optimal conditions of Al6061 were a 700 W core beam, a 500 W ring beam and 200 mm/s of weld speed. For the C1020P, the optimum conditions were a center beam of 2500 W, a ring beam of 3000 W and a welding speed of 200 mm/s. In laser lap welding of Al-Al and Al-Cu, the bead width and the interfacial bead width of the joint increased as the output increased. The penetration depth did not change significantly, but small pores were formed at the interface of the junction. Tensile tests were performed to demonstrate the reliability of the weld zone, and computer simulations provided analysis of the heat distribution for optimal heat input conditions.

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