Title:  Adiabaticity and symmetry in optical waveguide design

 

Speaker: 유경식 (KAIST 전기및전자공학부)

 

Date: 4pm, 28th April

 

Place: E6 1323 (Available seats can be limited because of the COVID situation.)

Zoom address: https://kaist.zoom.us/j/8750675930?pwd=azkxV2FaRTR5NVpmL2RmYmpzd0g0Zz09

 

'Adiabaticity' and 'shortcuts to adiabaticity' are important concepts in many aspects of modern physics. In this talk, we discuss two specific examples of optical waveguide designs that involve adiabatic photonic state evolutions with potential applications in photonic integrated circuits. The first example is highly-efficient broadband adiabatic mode transformation between single-mode optical fibers and integrated silicon waveguides. Based on adiabatic mode transformation through tapered optical waveguides, we show that high-efficiency optical energy transfer between dissimilar waveguides can be achieved for building  seamless interfaces between heterogeneous photonic systems. The second example is strong time-asymmetric optical transmission near an exceptional point involving non-adiabatic state jumps. Using the conventional photonic integrated circuits platform, we experimentally verify that time-asymmetric responses can be obtained in a non-Hermitian dynamic system without encircling an exceptional point by carefully controlling evolution dynamics.