title: Optimum access waveguide width for 1 x N multimode interference couplers on silicon nanomembrane.
abstract: We derived an analytical formula for the optimum width of the access waveguides of 1 x N multimode interference (MMI) couplers. Eigenmode-decomposition-based simulations show that the optimum width relation corresponds to the points of diminishing returns in both insertion loss and output uniformity versus access waveguide width. We fabricate and characterize 1 x 12 MMI couplers on a nanomembrane of silicon-on-insulator substrate. The experimental investigations demonstrate that the analytical results can be reliably used as a design rule for MMI couplers with large number of outputs.
authors.affiliation: Microelectronic Research Center, Department of Electrical and Computer Engineering, University of Texas, 10100 Burnet Road, Austin, Texas 78758, USA. ahoss@mail.utexas.edu
authors.forename: Amir
authors.initials: A
authors.lastname: Hosseini
authors.forename: Harish
authors.initials: H
authors.lastname: Subbaraman
authors.forename: David
authors.initials: D
authors.lastname: Kwong
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ray T
authors.initials: RT
authors.lastname: Chen