Laser surface structuring of diamond with ultrashort Bessel beams

Author(s):

Sanjeev Kumar, Shane M. Eaton, Monica Bollani, Belén Sotillo, Andrea Chiappini, Maurizio Ferrari, Roberta Ramponi, Paolo Di Trapani, Ottavia Jedrkiewicz

Abstract:

“We investigate the effect of ultrafast laser surface machining on a monocrystalline synthetic diamond sample by means of pulsed Bessel beams. We discuss the differences of the trench-like microstructures generated in various experimental conditions, by varying the beam cone angle, the energy and pulse duration, and we present a brief comparison of the results with those obtained with the same technique on a sapphire sample. In diamond, we obtain V-shaped trenches whose surface width varies with the cone angle, and which are featured by micrometer sized channels having depths in the range of 10–20 μm. By laser writing crossed trenches we are also able to create and tailor on the diamond surface pillar-like or tip-like microstructures potentially interesting for large surface functionalization, cells capturing and biosensing.”

Link to Publications Page

Publication: Scientific Reports

Issue/Year/DOI: Scientific Reports 8, Article number: 14021 (2018)

DOI: 10.1038/s41598-018-32415-0

High efficiency fabrication of complex microtube arrays by scanning focused femtosecond laser Bessel beam for trapping/releasing biological cells

Author(s):

Liang Yang and Shengyun Ji and Kenan Xie and Wenqiang Du and Bingjie Liu and Yanlei Hu and Jiawen Li and Gang Zhao and Dong Wu and Wenhao Huang and Suling Liu and Hongyuan Jiang and Jiaru Chu

Abstract:

“In this paper, we present a focused femtosecond laser Bessel beam scanning technique for the rapid fabrication of large-area 3D complex microtube arrays. The femtosecond laser beam is converted into several Bessel beams by two-dimensional phase modulation using a spatial light modulator. By scanning the focused Bessel beam along a designed route, microtubes with variable size and flexible geometry are rapidly fabricated by two-photon polymerization. The fabrication time is reduced by two orders of magnitude in comparison with conventional point-to-point scanning. Moreover, we construct an effective microoperating system for single cell manipulation using microtube arrays, and demonstrate its use in the capture, transfer, and release of embryonic fibroblast mouse cells as well as human breast cancer cells. The new fabrication strategy provides a novel method for the rapid fabrication of functional devices using a flexibly tailored laser beam.”

Link to Publications Page

Publication: Optics Express

Issue/Year/DOI: Optics Express Vol. 25, Issue 7, pp. 8144-8157 (2017)

DOI: 10.1364/OE.25.008144

 

Application of cooled spatial light modulator for high power nanosecond laser micromachining

Author(s): Rainer J. Beck, Jonathan P. Parry, William N. MacPherson, Andrew Waddie, Nick J. Weston, Jonathan D. Shephard, and Duncan P. Hand

Abstract:

“The application of a commercially available spatial light modulator (SLM) to control the spatial intensity distribution of a nanosecond pulsed laser for micromachining is described for the first time. Heat sinking is introduced to increase the average power handling capabilities of the SLM beyond recommended limits by the manufacturer. Complex intensity patterns are generated, using the Inverse Fourier Transform Algorithm, and example laser machining is demonstrated. The SLM enables both complex beam shaping and also beam steering.”

Link to Publications Page

Publication: Optics Express, (free download)

Issue/Year/DOI: Optics Express, Vol. 18, Issue 16, pp. 17059-17065 (2010)
doi:10.1364/OE.18.017059

Parallel photopolymerisation with complex light patterns generated by diffractive optical elements

Author(s): Lóránd Kelemen, Sándor Valkai, and Pál Ormos

Abstract:

“Photopolymerisation by scanning a focused laser beam is a powerful method to build structures of arbitrary complexity with submicrometer resolution. We introduce parallel photopolymerisation to enhance the efficiency. Instead of multidimensional scanning of a single focus, the structure is generated simultaneously with diffractive patterns. We used fixed diffractive optical elements (DOEs), kinoforms, and Spatial Light Modulators (SLMs). The possibilities of photopolymerisation using SLM were investigated: the added flexibility using the programmable device is demonstrated. By using these DOEs, straight and helical cross shaped columns were produced with a single scan at a rate about an order of magnitude faster than by simple scanning. The produced helical structures could be rotated by optical tweezers.”

Link to Publications Page

Publication: Optics Express, (free download)

Issue/Year/DOI: Optics Express, Vol. 15, Issue 22, pp. 14488-14497 (2007)
doi:10.1364/OE.15.014488