Polarization splitter based on a three waveguide directional coupler using quantum mechanical analogies

Abstract

We propose a novel waveguide polarization splitter based on the optical analogue of two-photon Rabi oscillations and stimulated Raman adiabatic passage in a three waveguide directional coupler. Both these processes are borrowed from three level quantum mechanical atomic systems, in which an intermediate level is used to transfer the population from one state to another without any population occupation in the intermediate level. To show the practical feasibility of the device, simulations have been carried out on waveguides in lithium niobate and we show that two orthogonal polarizations can be separated at the output using the proposed three waveguide structures. We also show that the proposed structure is robust against changes in phase mismatch parameters, as well as wavelength of operation.

Controllable multiple beam splitting in Hermitian and non-Hermitian symmetric coupled waveguide systems

“…Despite the advantages, adiabatic beam-splitting usually requires a sufficiently long distance or large coupling constant or both, which are undesirable in many experimental applications. To speed up the adiabatic process and design higher fidelity devices [35][36][37][38][39][40], shortcut to adiabaticity (STA) was employed to the coupled WG systems [41][42][43][44][45][46].…”

Controllable multiple beam splitting in Hermitian and non-Hermitian symmetric coupled waveguide systems

“…Despite the advantages, adiabatic beam-splitting usually requires a sufficiently long distance or large coupling constant or both, which are undesirable in many experimental applications. To speed up the adiabatic process and design higher fidelity devices [28][29][30][31][32][33], shortcut to adiabaticity (STA) was employed to the coupled waveguide systems [34][35][36][37][38][39].…”

Broadband integrated polarization beam splitting based on anisotropic adiabatic transfer of light

“…Combining the above STIRAP-like light transfer with waveguides showing a different propagation constant for the TE and TM polarizations can be exploited advantageously to realize an integrated PBS [22,23]. In the present work we propose an alternative and simple method, where no precise adjustment of the transverse shapes and dimensions of the waveguides is required to induced the difference in the TE and TM effective refractive indices.…”

“…The idea is to exploit directly the anisotropy of material. Few attempts have exploited material anisotropy to realize integrated PBSs, and the systems often require the integration of different materials in distinct parts or sections of the coupler [2,23,24], which increases the difficulty of the technological process. Here we demonstrate that a three-waveguide system can be built with the same anisotropic refractive index contrast for all waveguides.…”