A novel method to fabricate gapless hexagonal micro-lens array

Chou, Min-Chieh; Pan, Cheng‐Tang; Shen, Sheng-Chih; Chen, M. F.; Lin, Kuo-Chao; Wu, Sha

doi:10.1016/j.sna.2004.08.015

Cited by 42 publications

(24 citation statements)

References 21 publications

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“…It is clearly seen from Fig. 2(a) that the periodicity and uniform shape of the original template are well reserved in the PC mold and the fabricated PMMA MLAs preserve all the structural features from the PC mold except for a slight shape deformation for some microlenses, which may be attributed to the local shrinkage [34] of the PC and PMMA during cooling process, as shown in Fig. 2(b).…”

Section: Microlens Arrays Prepared Via Colloidal Microsphere Templatingmentioning

confidence: 86%

基于胶体微球模板制备微透镜阵列

Zhao¹,

Zhu²,

Zhan³

2010

中国光学快报

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A simple and efficient templating method in combination with hot embossing technique is developed for fabricating large-area two-dimensional (2D) microlens arrays (MLAs) with uniform shape. By utilizing a modified microchannel method, a 2D large-area hexagonal close-packed (HCP) array of silica colloidal microspheres is prepared and serves as a template in the following hot embossing treatment to create a polycarbonate (PC) microcavity array. Then, with the obtained PC microcavity structure serving as a mold, a hot embossing process is applied to finally achieve a polymethylmethacrylate (PMMA) MLA. The effect of annealing time during the mold preparation process on the dimensions and shapes of the prepared microlens is investigated. The imaging performances of the prepared PC concave microcavities and PMMA convex microlenses are characterized by carrying out projection experiments. Our method provides a rapid and low cost approach to prepare large-area MLAs.OCIS Microlens has been studied for decades due to its important applications in imaging, optic communication, and biochemical detection [1−7] . For example, compact all-fiber zone plate microlens fabricated at the end of a mode-expanded hybrid fiber can help focus emergent light remarkably [8,9] . With a pair of microlens arrays (MLAs), pupil densification can be achieved with improving the imaging performance of the hyper telescope [10] . Moreover, multidirectional asymmetrical MLAs have been fabricated and served as light-control films for enhancing the imaging quality of refractive liquid-crystal displays [11] . Up to now, many different approaches have been reported to fabricate MLAs with particular shape and dimension, including lithography-assisted thermal reflow process [12−19] , gray-scale lithography [20,21] , allliquid techniques [22−24] , and mask-assisted focus-ionbeam lithography [25,26] . However, the aforementioned methods more or less require complex experimental processes or expensive equipments. By contrast, the selforganization technique, commonly used for preparing masks or templates [27−29] , has provided a new way for fabricating MLAs with low cost and simple procedure. For example, Yabu et al. [30] have reported the preparation of hexagonally packed micropores structure by using self-assembled condensed water droplets as templates. Spherical MLAs have been successfully fabricated by directly molding from the resulting 'honeycomb' structure.In this letter, we present a simple and efficient templating method to fabricate large-area MLAs with uniform shape. Our method comprises two processes which are mold preparation and subsequent hot embossing. We show that the size control of the fabricated microlens can be achieved by varying the annealing time during mold preparation process or the size of the colloidal particles. Imaging performances of both polycarbonate (PC) concave and polymethylmethacrylate (PMMA) convex microlens prepared are further characterized and the image resolution is improved through tuning the dimensions of microl...

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Section: Microlens Arrays Prepared Via Colloidal Microsphere Templatingmentioning

confidence: 86%

基于胶体微球模板制备微透镜阵列

Zhao¹,

Zhu²,

Zhan³

2010

中国光学快报

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“…In many cases, how to make the fist molds or the original lens array profiles is the most important subject. Thermal reflow of resist patterns is a most popular method [1][2][3][4][5][6]. Lithography using gray tone masks is another typical method [7,8].…”

Section: Introductionmentioning

confidence: 99%

Characterization of Resist Molds and Replicated Nickel Dies for Fabricating Micro-Lens Arrays

Horiuchi

Sasaki

Komatsubara

et al. 2014

J. Photopol. Sci. Technol.

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A new method for fabricating metal dies for the use of micro-lens array molding or stamping was proposed and investigated. As a metal, nickel was used, and the nickel dies were fabricated by replicating the primary resist molds that were directly printed using projection lithography on silicon wafers coated with approximately 10-μm thick positive resist PMER P-LA900PM. Lens array patterns with quasi-spherical cross sections were printed by selecting a wavelength of 405-nm, defocuses between +100 and +200 μm and exposure times of 20-30 min. After printing resist mold patterns of a lens array, a thin gold film was spattered on it, and nickel was electroplated next. The aimed nickel dies were obtained by removing the resist molds from the electroplated nickel blocks. The diameters of nickel dies were faithfully corresponded to those of the resist molds. In addition, the surfaces of nickel dies were very smooth, and the peak-to-valley roughness was almost less than a quarter of visible light wavelengths. The new method will be promisingly effective for fabricating micro-lens arrays.

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“…Microstructures are attracting attentions for applications in the fields of optical communication, optical storage, flat panel displays, micro motors, micro robots, et al (1)(2)(3)(4)(5) . In order to guarantee the performance of the manufactured workpiece with microstructures, it is important to accurately measure the surface form of the microstructures.…”

Section: Introductionmentioning

confidence: 99%

Surface Form Measurement and Analysis of a Cylindrical Workpiece with Microstructures

Shimizu²,

Takeishi

et al. 2012

JAMDSM

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A measurement system is presented for the surface form measurement of a cylindrical workpiece with periodic microstructures generated on the outer surface of the workpiece. The main components of the measurement system are a spindle to rotate the workpiece, and an air-bearing displacement sensor with a diamond micro stylus to detect the surface form of the workpiece. The surface form of the micro-structured workpiece was measured in different rotation speeds and the relationship between the measurement repeatability and the rotation speed was investigated. The Fourier transform analysis and the wavelet transform analysis were employed to analyze the measurement results in the time-frequency domain for the identification of the error sources with specific frequency characteristics.

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A novel method to fabricate gapless hexagonal micro-lens array

Cited by 42 publications

References 21 publications

基于胶体微球模板制备微透镜阵列

基于胶体微球模板制备微透镜阵列

Characterization of Resist Molds and Replicated Nickel Dies for Fabricating Micro-Lens Arrays

Surface Form Measurement and Analysis of a Cylindrical Workpiece with Microstructures

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