Shalaby, MostafaPeccianti, MarcoOzturk, YavuzMorandotti, Roberto2019-10-272019-10-2720132041-1723https://doi.org/10.1038/ncomms2572https://hdl.handle.net/11454/47731A Faraday isolator is an electromagnetic non-reciprocal device, a key element in photonics. It is required to shield electromagnetic sources against the effect of back-reflected light, as well as to limit the detrimental effect of back-propagating spontaneous emissions. A common isolator variant, the circulator, is widely used to obtain a complete separation between forward-and backward-propagating waves, thus enabling the realization of a desired transfer function in reflection only. Here we demonstrate a non-reciprocal terahertz Faraday isolator, operating on a bandwidth exceeding one decade of frequency, a necessary requirement to achieve isolation with the (few-cycle) pulses generated by broadband sources. The exploited medium allows a broadband rotation, up to 194 degrees/T, obtained using a SrFe12O19 terahertz-transparent permanent magnet. This in turn enables the design of a stand-alone complete terahertz isolator without resorting to an external magnetic field bias, as opposed to all the optical isolators realized so far.en10.1038/ncomms2572info:eu-repo/semantics/openAccessArticle4WOS:00031887390001223463001Q1Q1