Ultrafast nonresonant third-order optical nonlinearity of a conjugated 3,3′-bipyridine derivative from 1150 to 1600 nm

A conjugated 3,3′-bipyridine derivative, an apolar structure of donor–acceptor–acceptor–donor (D–A–A–D) type was designed and characterized for third-order optical nonlinearity using Z-scan technique in the wavelength range of 1150–1600 nm. Z-scan spectra reveal a positive Kerr coefficient across this wavelength range with n2=(4.6±0.7)×10−6 cm2/GW at 1550 nm accompanied by negligible nonlinear absorption for wavelength around 1550 nm, indicating ideal figures of merit for applications in ultrafast all-optical switching.