Prospects for the implementation of magneto-optic elements in optoelectronic integrated circuits: a personal perspective

A review is performed of the major challenges to the implementation of the non-reciprocal functionality provided by magneto-optics in standard optoelectric or photonic integrated circuits. The polarization dynamics in the presence of an unavoidable, structurally-induced birefringence are discussed by making use of a Hamiltonian approach. Normally, the additional birefringence would place a limitation on the degree of polarization rotation achievable, but solutions based on quasi-phase-matching or the transverse Kerr effect are discussed. It is shown that the magneto-optic response of III-V semiconductors and other common substrate materials is small and some of the approaches to incorporating materials with a larger response are reviewed. Approaches to combining a polarization rotation element with the required polarization selectivity in a planar waveguide is also discussed.