Design and prototyping of beam shapers to generate circular or square top-hat beams of different size for additive manufacturing applications

Belay, Gebirie Yizengaw; Vervaeke, Michael; Liao, Shaowei; Ecker, Piet Van Den; Craeghs, Tom; Thienpont, Hugo; Erps, Jürgen Van

doi:10.1117/12.2555010

Cited by 3 publications

(2 citation statements)

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“…Stereolithography (SLA) 3D printers, using optical curing and using uncured resin as the sacrificial material, would optically overexpose by spillover intensity and blooming, because a square-profile optical beam is challenging to achieve in practice [ 8 , 9 , 10 ]. This phenomenon can be useful in bulk curing of homogeneous structures, but it is detrimental to printing fidelity at the intended boundary of the microchannel.…”

Section: Introductionmentioning

confidence: 99%

A Solution to the Clearance Problem of Sacrificial Material in 3D Printing of Microfluidic Devices

et al. 2022

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3D-printing is poised to enable remarkable advances in a variety of fields, such as artificial muscles, prosthetics, biomedical diagnostics, biofuel cells, flexible electronics, and military logistics. The advantages of automated monolithic fabrication are particularly attractive for complex embedded microfluidics in a wide range of applications. However, before this promise can be fulfilled, the basic problem of removal of sacrificial material from embedded microchannels must be solved. The presented work is an experimental proof of principle of a novel technique for clearance of sacrificial material from embedded microchannels in 3D-printed microfluidics. The technique demonstrates consistent performance (~40–75% clearance) in microchannels with printed width of ~200 µm and above. The presented technique is thus an important enabling tool in achieving the promise of 3D printing in microfluidics and its wide range of applications.

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Section: Introductionmentioning

confidence: 99%

A Solution to the Clearance Problem of Sacrificial Material in 3D Printing of Microfluidic Devices

et al. 2022

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“…Beam shaping lens has a wide range of applications in set-ups or devices with optical path, such as imaging, lithography, etc [1,2]. One of typical beam shaper is to generate a uniform intensity distribution from a Gaussian beam of a laser source [3]. A classical lens controls the propagation direction and the energy distribution of a beam by changing the optical path with the thickness variance of materials with high refractive index like quartz or silica according to the laws of ray optics developed by Snell.…”

Section: Introductionmentioning

confidence: 99%

The design of a beam shaping lens with flat surfaces and ultra-thin thickness to convert a Gaussian beam to a top-hat beam

Wang

Chen

2022

Thirteenth International Conference on Information Optics and Photonics (CIOP 2022)

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The beam shaping system to convert the Gaussian beam to top-hat beam is widely used in modem optics such as laser technologies. A general beam shaper is normally composed of a convex or concave lens in nonspherical or freeform, which is bulky in the optical path and turns to a barrier in size minorizing for a compact system. A novel beam shaper with a plane structure with flat surfaces on both bottom and top sides are provided in this paper. Taking advantages of the phase changes by the subwavelength structures and the general Fresnel principle for discrete structures, a metalens with beam shaping function is designed. The phase variation between a Gaussian beam and a top-hat beam is studied with Fourier optics and then is adopted to the layout of the beam shaping metalens. Afterwards, the finite domain time difference method is adopted to simulate the energy distribution of the modulated beam to study the effectiveness of the novel ultra-thin beam shaping metalens. Examples to convert the Gaussian beam to top-hat beam calculated with convex surface and nanopillar array with flat surfaces are illustrated in the paper to demonstrate and discuss the beam shaping results with the novel design in plane form and ultra-thin thickness. According to our study, a beam shaping lens with flat surfaces and thickness smaller than 1 um with the uniformity better than 98% can be achieved at wavelength of 790 nm. Variable beam shaping results could be obtained by the design method to figure out the phase distribution with ray optics and then design the metalens according to the desired phase modulation by arranging the subwavelength structures accordingly. Tue numerical results may pave the way for further design of metalens and offers a solution for compact systems with optical paths.

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Free-form broadband flat lenses for visible imaging

Meem¹,

Majumder²,

Menon³

2021

OSA Continuum

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In the absence of separate apertures, the size and focal length of a lens determines both its resolution and light-collection ability defined by numerical-aperture (NA) and f/#, respectively.We utilize free-form broadband-diffractive-optical elements (BDOEs) to create flat lenses that decouple NA from f#, whereby the resolution of the lens may be chosen independently from its lightcollection ability. Specifically, we designed, fabricated and characterized three BDOE lenses operating in the visible band (450nm-750nm), each with f/11.25, but with NAs of 0.00075, 0.0067 and 0.054, respectively. Simulations confirm that such decoupling is possible even at much higher NAs. Experiments confirm achromatic focusing and broadband imaging. One of the lenses exhibited a depth-of-focus almost 2 orders of magnitude larger than the diffraction limit. Such BDOE lenses could be very useful in focal-plane arrays with large pixel sizes, where light collection efficiency needs to be maintained. Furthermore, by abandoning rotational symmetry, one can achieve free-form geometries in the focal spot, such as a square that can more closely match the geometry of the sensor pixel.

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Design and prototyping of beam shapers to generate circular or square top-hat beams of different size for additive manufacturing applications

Cited by 3 publications

References 0 publications

A Solution to the Clearance Problem of Sacrificial Material in 3D Printing of Microfluidic Devices

A Solution to the Clearance Problem of Sacrificial Material in 3D Printing of Microfluidic Devices

The design of a beam shaping lens with flat surfaces and ultra-thin thickness to convert a Gaussian beam to a top-hat beam

Free-form broadband flat lenses for visible imaging

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