, Volume 28, Issue 4, pp 353-369

Asymmetric, adiabatic multipronged planar splitters


This paper analyses the adiabatic forked splitter, a device for separating the power in different modes of a multimoded waveguide into distinct, single-mode waveguides. The concept of two-mode separation in asymmetric Y-splitters is generalized to several modal channels, and the resulting multipronged devices are studied in detail, thus addressing important issues such as (1) the achievement of optimally-short devices, (2) the minimization of radiation loss, and (3) the splicing of the device to external optical components. An approximate relationship is derived between the number of modal channels and the required device length, thus showing that there is an upper limit of about four modal channels, for practical fabrication in planar geometry.