TY - JOUR

T1 - Influence of the surface and subsurface contaminants on laser-induced damage threshold of anti-reflection sub-wavelength structures working at 1064 nm

AU - Liu, Fei

AU - Jiao, Hongfei

AU - Ma, Bin

AU - Paschel, Sebastian

AU - Balasa, Istvan

AU - Ristau, Detlev

AU - Wang, Zhanshan

AU - Zhang, Jinlong

AU - Cheng, Xinbin

N1 - Funding Information: This work was supported by the National Natural Science Foundation of China (NSFC) (61522506, 61621001); NSAF (U1630124); Joint Sino-German Research Project (No. GZ1275); National Program on Key Research Project (2016YFA0200900). The authors thank Huoyao Chen from the University of Science and Technology of China for the fabrication of ARSS.

PY - 2020/2/21

Y1 - 2020/2/21

N2 - The anti-reflection sub-wavelength structures (ARSS) was proposed to be a promising approach for the antireflection (AR) laser application due to the higher laser-induced damage threshold (LIDT) and better spectral performance. In this paper, we designed and fabricated two-dimensional periodic ARSS, and investigated the influence of surface and subsurface contaminants on the LIDT of ARSS. It is found that the photoresist residues on the surface of as-produced ARSS directly induce laser damage at a fluence of 16 J/cm2. Oxygen plasma cleaning can remove most of the photoresist residues, however, the re-deposition layer formed during the ion beam etching process are detrimental enough to trigger laser-induced damage at a relatively low fluence of 24 J/cm2. An optimal ultrasonic cleaning was developed to etch the re-deposition layer in the ARSS and the LIDT of the ARSS was significantly increased to 56 J/cm2, which is comparable to LIDT of the bare fused silica substrate. It illustrated that the surface and subsurface contaminants affect the LIDT of ARSS significantly. Moreover, the damage behaviors of ARSS were further investigated utilizing artificial nano-sized gold particles as the surface contaminants compared to the AR coating and bare fused silica substrate. The LIDT is influenced significantly by nano-sized gold particles for ARSS due to the electric field enhancement, while the LIDT decreased slightly in the case of AR coating and bare fused silica substrate. It verified that the surface and subsurface contaminants are much more critical key precursor to the laser-induced damage of ARSS.

AB - The anti-reflection sub-wavelength structures (ARSS) was proposed to be a promising approach for the antireflection (AR) laser application due to the higher laser-induced damage threshold (LIDT) and better spectral performance. In this paper, we designed and fabricated two-dimensional periodic ARSS, and investigated the influence of surface and subsurface contaminants on the LIDT of ARSS. It is found that the photoresist residues on the surface of as-produced ARSS directly induce laser damage at a fluence of 16 J/cm2. Oxygen plasma cleaning can remove most of the photoresist residues, however, the re-deposition layer formed during the ion beam etching process are detrimental enough to trigger laser-induced damage at a relatively low fluence of 24 J/cm2. An optimal ultrasonic cleaning was developed to etch the re-deposition layer in the ARSS and the LIDT of the ARSS was significantly increased to 56 J/cm2, which is comparable to LIDT of the bare fused silica substrate. It illustrated that the surface and subsurface contaminants affect the LIDT of ARSS significantly. Moreover, the damage behaviors of ARSS were further investigated utilizing artificial nano-sized gold particles as the surface contaminants compared to the AR coating and bare fused silica substrate. The LIDT is influenced significantly by nano-sized gold particles for ARSS due to the electric field enhancement, while the LIDT decreased slightly in the case of AR coating and bare fused silica substrate. It verified that the surface and subsurface contaminants are much more critical key precursor to the laser-induced damage of ARSS.

KW - Antireflection

KW - Laser-induced damage

KW - Subwavelength structures

UR - http://www.scopus.com/inward/record.url?scp=85079593603&partnerID=8YFLogxK

U2 - 10.1016/j.optlastec.2020.106144

DO - 10.1016/j.optlastec.2020.106144

M3 - Article

AN - SCOPUS:85079593603

VL - 127

JO - Optics and Laser Technology

JF - Optics and Laser Technology

SN - 0030-3992

M1 - 106144

ER -