Ultralow-loss silicon waveguide crossing using Bloch modes in index-engineered cascaded multimode-interference couplers

作者：Zhang Yang^*; Hosseini Amir; Xu Xiaochuan; Kwong David; Chen Ray T

来源：Optics Letters, 2013, 38(18): 3608-3611.

DOI：10.1364/OL.38.003608

We investigate the loss mechanism in three-moded multimode-interference couplers that are the building blocks of a compact and low-loss waveguide crossing structure. Broadband silicon waveguide crossing arrays with <0.01 dB insertion loss per crossing are proposed using cascaded multimode-interference couplers, where lateral subwavelength nanostructures are used to reduce the insertions loss. We design and fabricate a 101 x 101 waveguide crossing array with a pitch of 3.08 mu m. Insertion loss of similar to 0.02 dB per crossing and crosstalk <-40 dB at 1550 nm operating wavelength and a broad transmission spectrum ranging from 1520 to 1610 nm are experimentally demonstrated.

• 出版日期2013-9-15