Coupled-Waveguide Devices using Shortcuts to Adiabaticity
Shuo-Yen Tseng1*
1Department of Photonics, National Cheng Kung University, Tainan, Taiwan
* presenting author:Shuo-Yen Tseng,
The analogy between the Schrödinger’s equation describing quantum dynamics and the paraxial wave equation for light propagation in guided wave structures has provided a useful laboratory to visualize a variety of coherent quantum phenomena. New optical devices with broadband characteristics and/or tolerance to fabrication errors have also been developed by taking advantage of such analogies using adiabatic passage techniques. However, the devices are usually longer than their non-adiabatic counterparts. In integrated optics, it is desirable to have device robustness against system parameter variations while maintaining the compactness.

Conceptually, the problem of power coupling between waveguides/modes in coupled waveguide devices is analogous to the problem of coherent quantum system state control with laser pulses, with the goal of performing precise and robust state transfer in a short time. In this framework, a family of protocols called shortcuts to adiabaticity (STA) has been developed to optimize quantum state transfer, providing design rules to shape the profile and phase of the laser pulses to achieve the desired transfer properties. Using the quantum-optical analogies in weakly-coupled waveguides, we have recently proposed a series of coupled-waveguide devices using the STA protocols including mode splitters/converters, directional couplers , mode-sorting asymmetric Y-junctions, and polarization rotators. In this work, the design and simulation of a variety of coupled-waveguide devices using STA will be discussed.

Keywords: quantum control, waveguides, adiabatic, shortcuts to adaibaticity