Method of fabricating an array of diffractive optical elements by using a direct laser lithography
- 26 Downloads
Recently, aspheric lenses have been developed to correct various aberrations and to produce optical elements with various functions. In particular, efforts have focused on fabrication miniaturized and compact elements that make the use of flat, diffractive optical elements such as zone plates to replace conventional lenses. Direct laser lithography is one of the typical methods used to manufacture such diffraction optical elements. By using a high magnification objective lens, it generates a laser beam with a spot size of less than 1 μm at the focal point. To produce a pattern, such as a diffraction grating, a chromium-coated surface is controllably exposed to this light. In this study, the process conditions for fabricating a zone plate using a direct laser lithography were studied by using an air-bearing type linear XY stage which can easily make various patterns including a zone plate array. The previous studies using a polar coordinate lithographic system have an advantage for fabricating the circular type zone plate because the system uses a rotational stage. It, however, is not proper to fabricate an array type diffractive optics element. In this study, we used a rectangular type lithographic system by using an XY stage and tested the fabrication issues such as a runout error. The optical performance of the zone plate array fabricated by the suggested method was also verified by experimental evaluation.
KeywordsLaser lithography Zone plate Diffractive optical elements Computer generated hologram
Unable to display preview. Download preview PDF.
- 4.Smith HI, Menon R, Patel A, Chao D, Walsh M, Barbastathis G (1994) Zone-plate-array lithography: A low-cost complement or competitor to scanning-electron-beam lithography. Microelectron Eng 33(4):567–572Google Scholar
- 5.Tripathi A, Chronis N (2011) A doublet microlens array for imaging micron sized objects. J Micromech Microeng 21(105024):1–6Google Scholar
- 8.Barea LA, von Zuben AA, M-Brahim T, Montagnoli AN, Hospital M, Frateschi N, and Cirino GA (2015) Fresnel zone plate array fabricated by Maskless lithography. 2015 30th symposium on microelectronics technology and devices (SBMicro)Google Scholar
- 12.Kim DI, Rhee HG, Song JB, Lee YW (2007) Laser output stabilization for direct laser writing system by using an acousto-optic modulator. Rev Sci Instrum 78(10):103110/1–103110/4Google Scholar
- 14.Poleshchuk AG, Churin EG, Koronkevich VP, Korolkov VP, Kharussov AA, Cherkashin VV, Kiryanov VP, Kiryanov AV, Kokarev SA, Verhoglyad AG (1999) Polar coordinate laser pattern generator for fabrication of diffractive optical elements with arbitrary structure. Appl Opt 38:1295–1301CrossRefGoogle Scholar
- 16.Harasaki A, Schmit J, Wyant JC (2000) Improved vertical-scanning interferometry. Appl Opt 39(13):2017–2115Google Scholar