scholarly journals FEMTOSECOND LASER SCRIBING OF SAPPHIRE AT WAVELENGTH 1040 AND 520 NM

Doklady BGUIR ◽  
2019 ◽  
pp. 152-156
Author(s):  
B. A. Shulenkova ◽  
E. V. Lutsenko ◽  
A. V. Danilchik ◽  
Ja. A. Solovjov ◽  
A. N. Pyatlitski ◽  
...  

Sapphire cutting is one of the largest markets in laser materials processing. Since sapphire is one of the hardest transparent materials its mechanical and optical properties made it the ideal choice for use in the production of various devices, such as LEDs and transistors, cover glasses of watches and mobile devices. Among existing laser- or diamond-based tools solutions, femtosecond laser scribing appear as a promising technology since this technology has the unique capacity to produce highly localized bulk modification owing to non-linear absorption. Sapphire cutting with solid-state lasers is well known for many years and has become a modern industrial process. However, achievable process speed and cut quality are still limited. The femtosecond laser scribing of sapphire was studied at wavelengths of 1040 and 520 nm, followed by wet etching in HNO3/HF solution to identify emerging defects. The morphology of the laser ablated sapphire surface was evaluated by scanning electron microscopy. It was shown that at the wavelength of 1040nm, the material was effectively removed from the surface; however, cracks on the surface were formed. The use of the second harmonic gave more accurate and deep cuts compared with the main frequency at the same conditions. At the wavelength of 520 nm, the cracks were formed anisotropically inside the volume of the material. Therefore, there is a potential application of the femtosecond laser scribing for the fabrication of sapphire-based devices.

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 670
Author(s):  
Wijayanti Dwi Astuti ◽  
Hiraku Matsukuma ◽  
Masaru Nakao ◽  
Kuangyi Li ◽  
Yuki Shimizu ◽  
...  

This paper proposes a new optical angle measurement method in the optical frequency domain based on second harmonic generation with a mode-locked femtosecond laser source by making use of the unique characteristic of the high peak power and wide spectral range of the femtosecond laser pulses. To get a wide measurable range of angle measurement, a theoretical calculation for several nonlinear optical crystals is performed. As a result, LiNbO3 crystal is employed in the proposed method. In the experiment, the validity of the use of a parabolic mirror is also demonstrated, where the chromatic aberration of the focusing beam caused the localization of second harmonic generation in our previous research. Moreover, an experimental demonstration is also carried out for the proposed angle measurement method. The measurable range of 10,000 arc-seconds is achieved.


1991 ◽  
Vol 43 (8) ◽  
pp. 4564-4567 ◽  
Author(s):  
T. Engers ◽  
W. Fendel ◽  
H. Schüler ◽  
H. Schulz ◽  
D. von der Linde

2017 ◽  
Vol 26 (4) ◽  
pp. 044202
Author(s):  
Zi-Ye Gao ◽  
Jiang-Feng Zhu ◽  
Zheng-Mao Wu ◽  
Zhi-Yi Wei ◽  
Hao-Hai Yu ◽  
...  

2015 ◽  
Vol 120 (2) ◽  
pp. 409-415 ◽  
Author(s):  
V. M. Gordienko ◽  
I. A. Zhvaniya ◽  
I. A. Makarov

2021 ◽  
Vol 255 ◽  
pp. 06003
Author(s):  
Rajeev Ranjan ◽  
Maria Antonietta Ferrara ◽  
Luigi Sirleto

In this work, the implementation of a femtosecond Stimulated Raman Scattering microscope, equipped with three femtosecond laser sources: a Titanium-Sapphire (Ti:Sa), an optical parametric oscillator (OPO), and a second harmonic generator (SHG); is presented. Our microscope is designed so that it can cover all the regions of Raman spectra, taking advantage of two possible laser combinations. The first, Ti:Sa and OPO laser beams, which cover the C-H region (>2800 cm-1 ) in stimulated Raman gain (SRG) modality, whereas the second, Ti:Sa and SHG laser beams, covering the C-H region and the fingerprint region in stimulated Raman losses (SRL) modality. The successful realization of the microscope is demonstrated, reporting images of polystyrene beads using both SRL and SRG modalities.


Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 979
Author(s):  
Xuan He ◽  
Qiming Liu ◽  
Matthieu Lancry ◽  
François Brisset ◽  
Bertrand Poumellec

We report on space-selective crystallization of congruent and polar Sr2TiSi2O8 crystals in a stoichiometric SrO-TiO2-SiO2 glass induced by (1030 nm, 300 fs) femtosecond laser irradiation. This allows us to compare with non-congruent laser-induced crystallization of polar LiNbO3 in non-stoichiometric Li2O-Nb2O5-SiO2 glass and gain information on the mechanism of nanocrystals orientation with the laser polarization that we pointed out previously. Using scanning electron microscopy (SEM), second harmonic generation (SHG), and electron backscattered diffraction (EBSD), we studied the laser-induced crystallization according to the laser processing parameters (pulse energy, pulse repetition rate, scanning speed). We found (1) a domain where the laser track is filled with crystals not perfectly textured (low energy), (2) a domain where an amorphous volume remains surrounded by a crystallized shell (high energy). This arises from Sr out-diffusion and may give rise to the crystallization of both SrTiO3 and Sr2TiSi2O8 phases at low speed. In the one-phase domain (at higher speed), the possibility to elaborate a tube with a perfect Fresnoite texture is found. A significant difference in size and morphology whereas the crystallization threshold remains similar is discussed based on glass thermal properties. Contrarily to Li2O-Nb2O5-SiO2 (LNS) glass, no domain of oriented nanocrystallization controlled by the laser polarization has been found in SrO-TiO2-SiO2 (STS) glass, which is attributed to the larger crystallization speed in STS glass. No nanogratings have also been found that is likely due to the congruency of the glass.


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