Suhara T, Kobayashi K, Nishihara H, Koyama J
Appl Opt. 1982 Jun 1;21(11):1966-71. doi: 10.1364/AO.21.001966.
Fresnel waveguide lenses having a graded-index (GRIN) distribution for the segmented quadratic phase modulation are demonstrated. The GRIN Fresnel lenses exhibit excellent focusing characteristics and a very high efficiency, both limited only by diffraction. Graded-index Fresnel lenses (F/5, 1-mm aperture) were fabricated for the first time in amorphous As(2)S(3) film waveguides on a thermally oxidized silicon substrate by the electron-beam direct writing technique. The nearly diffraction-limited focusing characteristics and a high efficiency (48%) were experimentally obtained. The theoretical analysis and fabrication process are presented, and experimental results are discussed on the focusing characteristics of the fabricated GRIN Fresnel waveguide lens.
展示了具有用于分段二次相位调制的渐变折射率（GRIN）分布的菲涅耳波导透镜。GRIN菲涅耳透镜表现出优异的聚焦特性和非常高的效率，两者都仅受衍射限制。通过电子束直写技术首次在热氧化硅衬底上的非晶As(2)S(3)薄膜波导中制造了渐变折射率菲涅耳透镜（F/5，1毫米孔径）。通过实验获得了接近衍射极限的聚焦特性和高效率（48%）。给出了理论分析和制造工艺，并讨论了所制造的GRIN菲涅耳波导透镜聚焦特性的实验结果。
