Optical isolator

摘要

Various optical isolator embodiments are disclosed. Embodiments comprise a waveguide section utilizing materials that induce a propagation constant shift that is propagation-direction-dependent. Embodiments are characterized by a cutoff frequency for forward propagating waves that is different than the cutoff frequency for reverse waves. A particular embodiment is constructed as a single-mode waveguide on a substrate. The cross-section of the waveguide is inhomogeneous in terms of materials. This inhomogeneity induces a propagation constant shift, which is propagation-direction-dependent. This device works as an optical isolator from the cut-off frequency of the lowest forward wave (lower frequency) to one for the lowest reverse wave (higher frequency). Various configurations consistent with the principles of the invention are disclosed.

主权项

1. An optical isolator comprising:
a waveguide on a substrate, the waveguide being dimensioned to operate in a single mode for a selected frequency range and the waveguide further being structured such that, given magneto-optical properties of the waveguide's material, the waveguide has a cutoff frequency in a forward propagation direction that is different than a cutoff frequency in a reverse propagation direction.