Low-loss, high-bandwidth fiber-to-chip coupling using capped adiabatic tapered fibers
Low-loss, high-bandwidth fiber-to-chip coupling using capped adiabatic tapered fibers
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DOI：
10.1063/1.5145105
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发表时间：
2020-05-01
期刊：
影响因子：
5.6
通讯作者：
Shainline, Jeffrey M.
中科院分区：
文献类型：
--
作者：
Khan, Saeed;Buckley, Sonia M.;Shainline, Jeffrey M.
我们展示了在亚微米尖端终止的锥形光纤，该尖端包层有用于耦合到片上波导的较高折射率材料。该包层使得能够耦合到高折射率波导，而不会将光损失到掩埋氧化物。介绍了一种用高折射率聚合物包层拉锥光纤尖端的技术。研究了传统的锥形波导和分叉锥形波导结构用于包层光纤到片上波导的耦合。我们发现分叉波导有利于对准和封装，而传统的锥形波导则带来更高的带宽。从光纤通过分叉耦合器到亚微米氮化硅波导的插入损耗为1.1dB，3dB带宽为90nm。封装器件的耦合损耗为1.3 dB。在光纤耦合到传统锥形波导的情况下，损耗为1.4dB，其中3dB带宽延伸超出测量设备的范围，估计超过250nm。
We demonstrate adiabatically tapered fibers terminating in sub-micron tips that are clad with a higher-index material for coupling to an on-chip waveguide. This cladding enables coupling to a high-index waveguide without losing light to the buried oxide. A technique to clad the tip of the tapered fiber with a higher-index polymer is introduced. Conventional tapered waveguides and forked tapered waveguide structures are investigated for coupling from the clad fiber to the on-chip waveguide. We find the forked waveguide facilitates alignment and packaging, while the conventional taper leads to higher bandwidth. The insertion loss from a fiber through a forked coupler to a sub-micron silicon nitride waveguide is 1.1 dB and the 3 dB bandwidth is 90 nm. The coupling loss in the packaged device is 1.3 dB. With a fiber coupled to a conventional tapered waveguide, the loss is 1.4 dB with a 3 dB bandwidth extending beyond the range of the measurement apparatus, estimated to exceed 250 nm.