Magnetoplasmonic isolators utilizing the nonreciprocal phase shift.

We propose a long-range magnetoplasmonic waveguide structure, based on cerium-substituted yttrium iron garnets, that is capable of achieving a useful π/2 nonreciprocal phase shift within one propagation length. Incorporating this plasmonic geometry into a Mach-Zehnder interferometer allows for the implementation of an efficient, integrable isolator scheme with an insertion loss of 2.51 dB and an extinction ratio of 22.82 dB. With a small footprint of 6.4×10(-3)  mm(2) and nanoscale waveguide dimensions, we envision this device to be a key building block in the development of nanoplasmonic integrated circuitry.