結合繞射光學元件與梯度折射率元件之複合光學元件

Abstract

為了增加光學元件的功能及結構緊密程度，以應用在積體光學方面上，本論文中提出一種不同於以往的複合光學元件組合，一種由繞射光學元件及梯度折射率分佈元件所形成的複合光學元件，我們嘗試以光柵、Fresnel lens、電腦全像片等不同的表面蝕刻型繞射元件，與一維的梯度折射率分佈或二維的梯度折射分佈微透鏡做結合，設計出幾組複合元件，再以嚴格耦合波理論、光學追跡法及Huygens-Fresnel繞射原理，分別探討不同繞射元件與不同梯度折射率分佈結合之後的性能，並與其成分個別元件或相同的傳統元件的性能，做模擬比較；此外，為了達到其最大功能，在一般可實現的光學元件製程條件之下，我們找出最佳設計參數的條件，由此得知此類複合元件具有多功能、緊密結合、針對需求作最佳化設計等優點，其應用範圍也更加廣泛。

In order to enhance the functions and compactness of the optical elements for the applications to integrated optics devices, we propose a different type of hybrid optical elements. It is consist of diffractive optical elements and a gradient-index(GRIN) distribution elements1. We have designed several hybrid elements with surface relief diffractive optical elements, such as gratings, a Fresnel lens, and CGH(computer-generation-hologram), and one-dimension GRIN distribution element or a two-dimension GRIN lens. Then we analyze these different hybrid optical elements with rigorous coupled-wave theory, ray-tracing method, and Huygens-Fresnel diffraction theory. Besides, we compare the performance of these hybrid optical elements with those of an individual element and other conventional hybrid optical elements based on simulation results. Moreover, for best performances, we find out the conditions for the optimum optical designs and the practicability to fabricating optical elements. As a conclusion, these hybrid optical elements are functional, compact, and possible to optimize optical design for some applications. In other words, such kind of hybrid elements will be suitable for more applications.