Rapid Fabrication of Continuous Surface Fresnel Microlens Array by Femtosecond Laser Focal Field Engineering.

Linyu Yan,Qihuang Gong,Dong Yang,Yan Li

doi:10.3390/mi11020112

Linyu Yan, Qihuang Gong + Show 2 more

Open Access

https://doi.org/10.3390/mi11020112

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Abstract

Femtosecond laser direct writing through two-photon polymerization has been widely used in precision fabrication of three-dimensional microstructures but is usually time consuming. In this article, we report the rapid fabrication of continuous surface Fresnel lens array through femtosecond laser three-dimensional focal field engineering. Each Fresnel lens is formed by continuous two-photon polymerization of the two-dimensional slices of the whole structure with one-dimensional scan of the corresponding two-dimensional engineered intensity distribution. Moreover, we anneal the lens array to improve its focusing and imaging performance.

Highlights

Microlens is becoming an indispensable optical element in modern photonic devices
Arrays of Fresnel lens have been widely used in diverse optical devices such as scanners, charge-coupled device (CCD) image sensors [6] and pyroelectric infrared sensors [7], they provide great potential in optical interconnection of large-scale parallel computers [8]
PMriecrvoimoauchsinreess2e0a2r0c, h11e,sxhave shown that the focal field engineering has great potential in fabricatin2g o3fD8 structIunrtehsi[s2a2r]t.icle, we report on the rapid fabrication of continuous surface Fresnel lens array with the 3IDn tfhoicsaal rftiiecllde,ewngeinreepeorirntgontothfaecrilaiptaitde ftahberifcaabtriiocnatoiofncosnpteineduooufsthsuertfwacoe-pFhreostnonel pleonlysmarerraizyawtioitnh. tFhuert3hDerfmocoarlefi, weledaennngeianletehreinlgentsoafrarcaiylittaoteimthperofavberiitcsaftoiocnussipnegeadnodfimthaegtiwngo-ppehrofotormn apnoclye.merization

Summary

Introduction

Microlens is becoming an indispensable optical element in modern photonic devices. Among several kinds of microlens, benefiting from the advantages of compactness, lightweight construction, high numerical aperture, short-focal length, and excellent focusing capability, the Fresnel lens has found practical applications in integrated optical systems, such as solar distillation concentrator [1], optical multiplexer/demultiplexer [2,3], infrared-laser beam scanning system [4] and fluorescence detector for ultra-high energy cosmic ray observation [5]. Femtosecond laser direct writing TPP, which utilizes high intensity laser-induced two-photon absorption to initiate polymerization, is a potential microstructure fabrication technology with high precision and true three-dimensional (3D) configuration [11]. It has been considered as a promising method for micro-optical devices [12,13,14], microfluidic device, tissue engineering [15,16,17], etc. LAMcc,otrhdeinvgeltoocitthye othf itchkenXesYsZo-fstthageesliiscessetantod bthee6sμwmitc/sh.inItgosnpleyetdakoef sth6e.7SLs Mto, ftahbervicealoteciatyFroefstnheel XleYnZs.-stage is set to be 6 μm/s It only takes 6.7 s to fabricate a Fresnel lens

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