标题： 低弯曲损耗波导能够实现紧凑且高效的三维光子芯片 显示英文标题

标题： Low bend loss waveguides enable compact, efficient 3D photonic chips

摘要： 我们提出了一种新颖的方法来制造低弯曲损耗的飞秒激光直写的波导，该方法利用了激光诱导折射率变化的不同热稳定性。 该技术包括两步过程；第一步涉及制造大尺寸多模波导，而第二步则包括一个热退火过程，该过程会擦除折射率分布的外环，从而实现在C波段的单模操作。 通过使用此程序，我们报告了具有陡弯（小至16.6毫米半径）和高（80%）归一化透过率的波导。 这一程序首次被用于制造高效的三维光子器件，即瞳孔重映射器，并且几乎没有弯曲损耗。 该工艺还将允许基于数十到数百个波导的复杂芯片以紧凑的外形实现，并且具有较短的制造时间。 显示英文摘要

摘要： We present a novel method to fabricate low bend loss femtosecond-laser written waveguides that exploits the differential thermal stabilities of laser induced refractive index modifications. The technique consists of a two-step process; the first involves fabricating large multimode waveguides, while the second step consists of a thermal post-annealing process, which erases the outer ring of the refractive index profile, enabling single mode operation in the C-band. By using this procedure we report waveguides with sharp bends (down to 16.6 mm radius) and high (80%) normalized throughputs. This procedure was used to fabricate an efficient 3D, photonic device known as a pupil-remapper with negligible bend losses for the first time. The process will also allow for complex chips, based on 10's - 100's of waveguides to be realized in a compact foot print with short fabrication times.