分类： 光学 >> 量子光学 提交时间： 2023-02-19
摘要： We propose a novel coaxial spherical-lens shaping system to achieve a flat-top focus profile by exploiting the spherical aberration of the lens. The well-known aspherical-lens shaping system is compared to ours, and a comparison of etching on silicon is conducted between a Gaussian beam and the one shaped by the proposed system. Analytical and experimental results show that the proposed system is able to achieve flat-top beam shaping using only spherical lenses. Compared with the existing systems, our proposed one is capable of shaping Gaussian beams with different wavelengths and waist radii. Furthermore, the shaped one obtained by ours is the flat-top beam with extended depth of focus. This letter provides an efficient and precise flat-top beam shaping scheme for optics and laser technology, and increases the potential of spherical lenses in the field of laser shaping.
分类： 光学 >> 量子光学 提交时间： 2023-02-19
摘要： Bloch oscillations, an important transport phenomenon, have extensively been studied in static systems but remain largely unexplored in Floquet systems. Here, we propose a new type of Bloch oscillations, namely the "Floquet-Bloch oscillations," which refer to rescaled Bloch oscillations with a period of extended least common multiple of the modulation and Bloch periods. We report the first visual observation of such Floquet-Bloch oscillations in femtosecond-laser-written waveguide arrays by using waveguide fluorescence microscopy. These Floquet-Bloch oscillations exhibit exotic properties, such as fractal spectrum and fractional Floquet tunneling. This new transport mechanism offers an intriguing method of wave manipulation, which has significant applications in coherent quantum transport.
点击量
待评议
点击量
下载量
评论
