A magnetic non-reciprocal isolator for broadband terahertz operation

作者：Shalaby Mostafa; Peccianti Marco; Ozturk Yavuz; Morandotti Roberto^*

来源：Nature Communications, 2013, 4(1): 1558.

DOI：10.1038/ncomms2572

A 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.

• 出版日期2013-3