title: Arbitrary-ratio 1 × 2 power splitter based on asymmetric multimode interference.
abstract: Free choice of splitting ratio is one of the main properties of a power splitter required in integrated photonics, but conventional multimode interference (MMI) power splitters can only obtain a few discrete ratios. This Letter presents both numerical and experimental results of an arbitrary-ratio 1×2 MMI power splitter, which is constructed by simply breaking the symmetry of the multimode region. In the new device, the power splitting ratio can be adjusted continuously from 100:0 to 50:50, while the dimension of the multimode section stays in the range of 1.5×(1.8-2.8)  μm. The experimental data also indicate that the proposed arbitrary-ratio splitter keeps the original advantages of MMI devices, such as low excess loss, weak wavelength dependence, and large fabrication tolerance.
authors.forename: Qingzhong
authors.initials: Q
authors.lastname: Deng
authors.forename: Lu
authors.initials: L
authors.lastname: Liu
authors.forename: Xinbai
authors.initials: X
authors.lastname: Li
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Zhou