Hybrid(Refractive/Diffractive)Lens Design for Image Pick up

• Main Authors: Liu, Ming-Cheng, 劉明政
• Other Authors: 蕭金廷
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/09589784374905209568

碩士 === 輔仁大學 === 物理學系 === 94 === Abstract Micro-optical elements can be refractive, diffractive or hybrid (refractive/diffractive). The design of diffractive optical lenses provides more parameters to adjust the shape of wavefront, but its drawback is the strong negative dispersion. Diffractive optics are therefore mostly used with single color light. For broadband applications, DOE (diffractive of element) is combined with refractive optics to correct for the chromatic aberration. The combination allows systems with low weight, or which consist of only one material. DOE has not been largely applied to image pick-up lenses nowadays. DOE has to combine with refractive optics to correct dispersion, so it has many difficulties of merit function setting of designing. For lens designing, we expect to make one single hybrid lens to replace multiple lenses in tradition in order to minimize the size and to reduce the cost. At the beginning of the essay, we compare the differences between “refractive optical elements” and “diffractive optical elements”. Then, we introduce the fundamental theory of diffractive optical elements. Before designing the lens, we find out the specification of the sensor and use a formula to calculate the specification of the optical lens, which we need to design. With a lens designing software, ZEMAX, we design lenses in the order as following: bi-spherical, single aspheric, bi-aspheric refractive lenses and hybrid bi-aspheric diffractive lenses. Last, we compare the designing results and analyze their images. According to the designing result, a hybrid DOE lens indeed can correct chromatic aberration and improve the quality of images. Besides, the designing result has met the practical standard of element production. Keyword: hybrid (refractive/diffractive) element, merit function, chromatic aberration, quality of image.