Functional Segmentation Method for the Design of Compact Adiabatic Devices

Abstract

In this study, a functional segmentation method for the design of adiabatic devices is presented. This method can be applied to calculate the compact adiabatic waveguide shapes for adiabatic taper waveguides and adiabatic mode converters. We introduce two algorithms, namely the quadratic function segmentation design for the adiabatic taper waveguide and the cubic function segmentation design for the adiabatic mode coupler. The design shows that for each segment, there is no need for separate simulations to obtain the length of each segment, and only the length of each segment can be determined by equations. This approach is much less cumbersome than other numerical design methods for adiabatic devices. The proposed functional segmentation design requires only a device length of 36 μm to achieve 95% power transfer efficiency, while a traditional linear-shape connection requires a device length of 54 μm to achieve the same power transfer efficiency. Therefore, the device designed by the function segmentation method has better compactness compared to the conventional linear-shape connection design of adiabatic devices.