Hybrid 2D-3D optical devices for integrated optics by direct laser writing
Hybrid 2D-3D optical devices for integrated optics by direct laser writing
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DOI：
10.1038/lsa.2014.56
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发表时间：
2014-06-01
影响因子：
19.4
通讯作者：
Pernice, Wolfram
中科院分区：
文献类型：
--
作者：
Schumann, Martin;Bueckmann, Tiemo;Pernice, Wolfram
集成光学芯片已经被建立用于光通信。它们还为芯片上的集成量子光学提供了有趣的未来前景。然而，目前，它们主要是使用基本上平面的制造方法，如电子束光刻或UV光刻。如果人们在垂直于芯片的第三维方面具有完全的制造自由度，而不必放弃现有平面制造技术的优点和技术诀窍，则会出现许多进一步的设计选择。作为在这个方向上的一个步骤，我们在这里使用三维浸入直接激光写入光刻制作三维聚合物功能器件上预制的平面光学芯片包含Si3N4波导以及光栅耦合器由标准的电子束光刻。第一个例子是聚合物电介质矩形波导，其连接到Si3N4波导，并且沿其轴沿着螺旋扭曲，以实现芯片上线性偏振的几何旋转。该旋转器在1550 nm附近的宽带性能通过偏振相关光栅耦合器进行了验证。光学芯片上的这种偏振旋转不能通过其他手段容易地实现。第二个例子是通过聚合物波导连接到芯片上的Si3N4波导的回音壁模式光学谐振器。通过将后者机械连接到磁盘，我们可以控制与谐振器的耦合，同时保证芯片上三维结构的机械稳定性。
Integrated optical chips have already been established for application in optical communication. They also offer interesting future perspectives for integrated quantum optics on a chip. At present, however, they are mostly fabricated using essentially planar fabrication approaches like electron-beam lithography or UV optical lithography. Many further design options would arise if one had complete fabrication freedom in regard to the third dimension normal to the chip without having to give up the virtues and the know-how of existing planar fabrication technologies. As a step in this direction, we here use three-dimensional dip-in direct-laser-writing optical lithography to fabricate three-dimensional polymeric functional devices on pre-fabricated planar optical chips containing Si3N4 waveguides as well as grating couplers made by standard electron-beam lithography. The first example is a polymeric dielectric rectangular-shaped waveguide which is connected to Si3N4 waveguides and that is adiabatically twisted along its axis to achieve geometrical rotation of linear polarization on the chip. The rotator's broadband performance at around 1550 nm wavelength is verified by polarization-dependent grating couplers. Such polarization rotation on the optical chip cannot easily be achieved by other means. The second example is a whispering-gallery-mode optical resonator connected to Si3N4 waveguides on the chip via polymeric waveguides. By mechanically connecting the latter to the disk, we can control the coupling to the resonator and, at the same time, guarantee mechanical stability of the three-dimensional architecture on the chip.