Micro-replication of optical lenses in glass using a novel sol gel technology

Sayah, A.; Parashar, V.K.; Gijs, Martinus

doi:10.1109/memsys.2002.984322

Cited by 10 publications

(4 citation statements)

References 8 publications

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“…The image is approximately located at the focal plane of the microlens. The difference between these positions is a measure for the focal distance of the two tested microlens arrays [25]. The data adquisition accuracy of this setup is ±5 µm.…”

Section: Resultsmentioning

confidence: 99%

Fabrication of microlens arrays on soda-lima glasses with a Nd:YVO 4 laser

et al. 2011

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We present a laser direct-write technique that is capable of providing microlens arrays on soda-lime glass substrate from one step ablation process, permitting one to shorten the typical times of microlens fabrication with other direct-writing techniques. The technique is based on the combination of a Q-switched Nd:YVO 4 laser and a galvanometer system for addressing the output beam laser. The geometrical and optical parameters of the microlenses have been measured to characterize the microlens arrays produced on an area of 2 mm×2 mm. Focal length values around 118 μm have been obtained by measuring the sag and the diameter of the microlens with a confocal microscope (nondirect method) or directly, using a microscope objective with a CCD camera. The practicality of both methods is shown in the good agreement between the obtained results for the focal length of microlenses. By using a noncontact profilometer, the surface roughness of the microlens has been measured and compared with that of a glass substrate.

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Section: Resultsmentioning

confidence: 99%

Fabrication of microlens arrays on soda-lima glasses with a Nd:YVO 4 laser

et al. 2011

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“…Other approaches profit from the polymer microlenses fabrication techniques that are eventually transferred into glass, e.g., by dry etching [19,20] but at the expense of a reduced optical quality. Different fabrication strategies based on solgel materials can be found in the literature [21,22], some of them being analogous to polymer reflow fabrication techniques [23].…”

Section: Introductionmentioning

confidence: 99%

Dense arrays of millimeter-sized glass lenses fabricated at wafer-level

Albero¹,

Perrin²,

Bargiel³

et al. 2015

Opt. Express

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This paper presents the study of a fabrication technique of lenses arrays based on the reflow of glass inside cylindrical silicon cavities. Lenses whose sizes are out of the microfabrication standards are considered. In particular, the case of high fill factor arrays is discussed in detail since the proximity between lenses generates undesired effects. These effects, not experienced when lenses are sufficiently separated so that they can be considered as single items, are corrected by properly designing the silicon cavities. Complete topographic as well as optical characterizations are reported. The compatibility of materials with Micro-Opto-Electromechanical Systems (MOEMS) integration processes makes this technology attractive for the miniaturization of inspection systems, especially those devoted to imaging.

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“…This process, known as the sol-gel process, can be easily modified to prepare a desired glass network. We have realized arra ys of glass micro-optical elements like microlenses, channel gratings, holographic gratings, fresnel lenses using in-house developed sol-gel materials [4,5]. …”

mentioning

confidence: 99%

The Sol-Gel Process for Realisation of Optical Micro-Structures in Glass

Parashar

Sayah²,

Gijs³

2004

KEM

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Abstract.We have applied the sol-gel process to generate optical microstructures in glass using in-house developed sol-gel materials. The synthesis of our sol-gel glass materials is based on the formation of particles of controlled size from organo-metallic compounds. The overall shrinkage during annealing of the gel material is negligible and does not imply crack formation. Silica, titania and binar y oxides of silica titania oxide sol-gel materials have been used. A two-step pattern transfer is employed to replicate the structure in glass: first a polydimeth ylsiloxane (PDMS) replica is obtained from a Si, polymethylmethacr ylate (PMMA) or polyimide (P I) master structure, and secondly, a la yer of sol-gel material is applied on the PDMS `soft-replica' to get diffractive micro-/nano-structures in glass after drying and annealing. These structures are characterised b y a scanning electron microscope (SEM) and b y an optical diffraction setup. IntroductionSub-micrometer structures, particularl y optical elements, are necessar y in advanced microopto-electro-mechanical systems (MOEMS) and, therefore represent a research area of great importance. Such elements can today be fabricated through the use of expensive processes, like ion etching, e-beam/laser writing, which are limited in performance [1,2]. For example, it is difficult to obtain a smooth concave, convex or prismatic profile using these techniques; on the other hand, pol ymer/plastic materials are easily microfabricated using molding techniques and are currently in use for micro-optical applications [3]. However, for certain applications, plastic structures present problems, for example in those where optical components are exposed to strong irradiation, giving rise to degradation of the plastic polymer chains, or in applications where temperature of operation is strongl y var ying, so that incompatibilities between dilatation of plastic structures and glass parts lead to a deterioration of the optical device functioning. Therefore, an attractive option is to develop a molding technology in glass. However, the mechano-chemical inertness of glass makes it hard for microstructuring. The only possible wa y to replicate glass is the direct casting from a liquid solution. Melt molding of glass is not a feasible solution, but chemical processing of a glass using liquid precursors provides a better opportunity to microstructure glass components with desired physico-optical properties. This process, known as the sol-gel process, can be easily modified to prepare a desired glass network. We have realized arra ys of glass micro-optical elements like microlenses, channel gratings, holographic gratings, fresnel lenses using in-house developed sol-gel materials [4,5].

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Micro-replication of optical lenses in glass using a novel sol gel technology

Cited by 10 publications

References 8 publications

Fabrication of microlens arrays on soda-lima glasses with a Nd:YVO 4 laser

Fabrication of microlens arrays on soda-lima glasses with a Nd:YVO 4 laser

Dense arrays of millimeter-sized glass lenses fabricated at wafer-level

The Sol-Gel Process for Realisation of Optical Micro-Structures in Glass

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