Abstract
A nanosecond pulsed Nd:YAG laser was used to irradiate a sapphire substrate to produce 3-dimensional microstructures with sharp V-shaped grooves. In initial experiments, where single grooves were machined, a maximum taper angle of ~79° was obtained. At constant laser parameters, the taper angle remained constant. As the taper angle increases from a flat surface, the irradiated area increases while incident fluence decreases; once the incident fluence approaches the ablation threshold, the taper angle becomes constant. The taper angle could be controlled by the laser fluence, scanning speed and incident angle of the laser beam. Using these results, a kind of surface microstructure, comprised of micropyramids with steep walls, was successfully machined for optical measurement applications. The surface roughness, transmittance and crystallinity of the microstructure surface could be controlled by the laser scanning speed. By applying the taper formation mechanism proposed in this study, the micromachining of sharp microstructures with steep walls on various hard brittle materials becomes possible.
| Original language | English |
|---|---|
| Journal | Precision Engineering |
| DOIs | |
| Publication status | Accepted/In press - 2018 Jan 1 |
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Keywords
- Groove formation
- Hard brittle material
- Laser processing
- Microstructure
- Optical element micromachining
- Sapphire
- Taper formation
ASJC Scopus subject areas
- Engineering(all)
Cite this
Nanosecond pulsed laser irradiation of sapphire for developing microstructures with deep V-shaped grooves. / Takayama, Nozomi; Asaka, Shouhei; Yan, Jiwang.
In: Precision Engineering, 01.01.2018.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Nanosecond pulsed laser irradiation of sapphire for developing microstructures with deep V-shaped grooves
AU - Takayama, Nozomi
AU - Asaka, Shouhei
AU - Yan, Jiwang
PY - 2018/1/1
Y1 - 2018/1/1
N2 - A nanosecond pulsed Nd:YAG laser was used to irradiate a sapphire substrate to produce 3-dimensional microstructures with sharp V-shaped grooves. In initial experiments, where single grooves were machined, a maximum taper angle of ~79° was obtained. At constant laser parameters, the taper angle remained constant. As the taper angle increases from a flat surface, the irradiated area increases while incident fluence decreases; once the incident fluence approaches the ablation threshold, the taper angle becomes constant. The taper angle could be controlled by the laser fluence, scanning speed and incident angle of the laser beam. Using these results, a kind of surface microstructure, comprised of micropyramids with steep walls, was successfully machined for optical measurement applications. The surface roughness, transmittance and crystallinity of the microstructure surface could be controlled by the laser scanning speed. By applying the taper formation mechanism proposed in this study, the micromachining of sharp microstructures with steep walls on various hard brittle materials becomes possible.
AB - A nanosecond pulsed Nd:YAG laser was used to irradiate a sapphire substrate to produce 3-dimensional microstructures with sharp V-shaped grooves. In initial experiments, where single grooves were machined, a maximum taper angle of ~79° was obtained. At constant laser parameters, the taper angle remained constant. As the taper angle increases from a flat surface, the irradiated area increases while incident fluence decreases; once the incident fluence approaches the ablation threshold, the taper angle becomes constant. The taper angle could be controlled by the laser fluence, scanning speed and incident angle of the laser beam. Using these results, a kind of surface microstructure, comprised of micropyramids with steep walls, was successfully machined for optical measurement applications. The surface roughness, transmittance and crystallinity of the microstructure surface could be controlled by the laser scanning speed. By applying the taper formation mechanism proposed in this study, the micromachining of sharp microstructures with steep walls on various hard brittle materials becomes possible.
KW - Groove formation
KW - Hard brittle material
KW - Laser processing
KW - Microstructure
KW - Optical element micromachining
KW - Sapphire
KW - Taper formation
UR - http://www.scopus.com/inward/record.url?scp=85042351002&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85042351002&partnerID=8YFLogxK
U2 - 10.1016/j.precisioneng.2018.02.008
DO - 10.1016/j.precisioneng.2018.02.008
M3 - Article
AN - SCOPUS:85042351002
JO - Precision Engineering
JF - Precision Engineering
SN - 0141-6359
ER -