Metasurfaces for broadband quadratic phase

Conventional dispersion and multi-resonant surfaces graphic.
Conventional dispersion compensation is either broadband or compact. Multi-resonant metasurfaces can enable arbitrary broadband, low loss,
quadratic dispersion compensation and chirping by an ultra-thin surface.
Scientific Achievement

Ultra-thin metasurfaces with a specific multi-resonant response can enable simultaneously arbitrarily strong and arbitrarily broadband dispersion compensation, pulse (de)chirping, & compression or broadening with low loss. 

Significance and Impact

This work overcomes the fundamental limitations of both conventional non-resonant approaches (bulky) & modern singly resonant metasurfaces (narrowband) for quadratic phase manipulations of electromagnetic signals, which is especially relevant to high-speed optical communication. 

Research Details
  • The nonuniform trains of electric and magnetic resonances that allow to completely control phase delay, group delay, and chirp are rigorously derived & the fundamental limitations revealed.
  • We construct practical, physically realizable approximations by finite sequences of linear resonances & rigorously quantify the associated error. This works in either transmission or reflection.

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