Theoretical seminar | 20 July 2022

 
Mr. Shahab Ramezanpour
ITMO University
Structure of Whispering Gallery Mode and Exceptional Point in Perturbed and Nonlinear System
Abstract

The term "exceptional point" (EP) refers to a singularity in non-Hermitian systems that demonstrates unusual features including strong sensitivity to outside disturbances and exquisite selectivity of a laser mode that results from a sudden change in the eigenvalue spectra. The real and imaginary components of two or more eigenfrequencies must coincide for EP to occur. Changes made throughout the production process frequently cause the degeneracy to rise, making it difficult to observe EP experimentally. We plan to tune the system to the EP even in the presence of a detuning parameter, using nonlinearity  and  nanoscatterer. Besides, using nanaoscatter in the coupling region of the coupled resonators, we can achieve EP with high chirality.