An electro-optic tunable microwave delay-line using the piezoelectric-piezomagnetic superlattices with an external DC electric field.

• The group velocity can be tuned freely by the external DC electric field. • The slow-wave factors on the forward and backward directions are asymmetric. • The proposed PPSs have an electro-optic tunable wavelength selection function. An Electro-optic tunable microwave slow-light delay-line using the piezoelectric (PZT) and piezomagnetic (CoFe 2 O 4) superlattices (PPSs) with the external DC electric field is presented. Asymmetric coupled polaritonic band structures with respect to the forward and backward directions are induced by time-space inversion symmetry breaking due to the coexistence of ferroelectric and ferromagnetic domains. The group velocity and time-delays of electromagnetic waves in the proposed PPSs can be tuned freely by the external DC electric field via the electro-optic effect. The tunability is continuous and reversible. Thus, the proposed PPSs has a switch function that can realize the free switching between fast and slow waves by the external DC electric field. The slow-wave factors with regard to the forward and backward directions are also asymmetric. In addition, transmission spectra show that the proposed PPSs have an electro-optic tunable wavelength selection function. [ABSTRACT FROM AUTHOR]