Automatic Image Analysis for Processing Marks in Femtosecond Laser Micromachining Using Concave and Convex Coefficient

In this paper, we demonstrate automatic image analysis for processing marks in femtosecond laser micromachining using concave and convex (unevenness) coefficient. To realize laser processing without thermal deformation and cracks, it's important to search optimum processing conditions such as s...

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Bibliographic Details
Published inJournal of laser micro nanoengineering Vol. 17; no. 1; pp. 12 - 18
Main Authors Aoki, Daisuke, Tamaki, Takayuki
Format Journal Article
LanguageEnglish
Published Ibaraki Japan Laser Processing Society 01.07.2022
Reza Netsu Kako Kenkyukai
Subjects
Cameras
Coefficients
Discriminant analysis
Femtosecond pulsed lasers
Glass substrates
Image analysis
Laser machining
Laser processing
Lasers
Methods
Micromachining
Pulse duration
Scanning
Straightness
Unevenness
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Summary:In this paper, we demonstrate automatic image analysis for processing marks in femtosecond laser micromachining using concave and convex (unevenness) coefficient. To realize laser processing without thermal deformation and cracks, it's important to search optimum processing conditions such as scanning speed and pulse energy. Therefore, we analyzed a set of microscope image during laser microprocessing of glass, and evaluated the morphology such as depth and straightness of processing marks. For the laser microprocessing, an ultrashort laser system (Fianium, FP1060S-PP-D) with a wavelength of 1.06 [mu]m, a pulse duration of 250 fs, and a repetition rate of 1 MHz was used. The sample to be processed was white glass substrates. The sample, which was mounted on the threedimensional stage, was scanned 10 mm in the x-axis direction with a scan speed of 0.1, 0.5, 1, and 2 mm/s. Also, for the laser microprocessing, the pulse energy was changed from 0.9 to 1.3 [mu]J. After laser microprocessing, processed mark was analyzed with concave and convex coefficient and Otsu's method. By making use of the concave and convex coefficient, luminance unevenness was reduced. We will introduce relationship between "scanning speed and/or pulse energy" and "gray scale and/or straightness of processing marks". Keywords: laser machining, image processing, image analysis, femtosecond laser, optimization, concave and convex coefficient, Otsu's method, unevenness
ISSN:1880-0688
1880-0688
DOI:10.2961/jlmn.2022.01.2003