An optical isolator core includes: a first birefringent crystal, a Faraday rotator, a second birefringent crystal, and a third birefringent crystal that are successively arranged along a forward optical path. In response to forward o light and forward e light successively traveling through the aforementioned optical elements, displacements of exit points of the forward o light and the forward e light with respect to an incident point are the same, and the forward o light and the forward e light are merged as exiting forward light. In response to backward o light and backward e light successively reversely traveling through the aforementioned optical element, displacements of exit points of the backward o light and the backward e light with respect to the incident point of the forward light causes the backward o light and the backward e light to deviate from the forward optical path.

An isolator includes a first core, a second core, a nonreciprocal member, and a magnetic body. The first core and the second core extend in a first direction and are positioned side by side with a cladding therebetween in a second direction that intersects the first direction. The nonreciprocal member is in contact with at least a part of the second core while being positioned side by side with the second core in the second direction. In a magnetic field generated by the magnetic body in a portion where the nonreciprocal member is positioned, a component in a third direction perpendicular to the first direction and the second direction is greater than any component other than the component in the third direction.

Embodiments herein relate to photonic integrated circuits with an on-chip optical isolator. A photonic transmitter chip may include a laser and an on-chip isolator optically coupled with the laser that includes an optical waveguide having a section coupled with a magneto-optic liquid phase epitaxy grown garnet film. In some embodiments, a cladding may be coupled with the garnet film, the on-chip isolator may be arranged in a Mach-Zehnder interferometer configuration, the waveguide may include one or more polarization rotators, and/or the garnet film may be formed of a material from a rare-earth garnet family. Other embodiments may be described and/or claimed.

There is set forth herein an integrated photonics structure having a waveguide disposed within a dielectric stack of the integrated photonics structure, wherein the integrated photonics structure further includes a field generating electrically conductive structure disposed within the dielectric stack; and a heterogenous structure attached to the integrated photonics structure, the heterogenous structure having field sensitive material that is sensitive to a field generated by the field generating electrically conductive structure. There is set forth herein a method including fabricating an integrated photonics structure, wherein the fabricating an integrated photonics structure includes fabricating a waveguide within a dielectric stack, wherein the fabricating an integrated photonics structure further includes fabricating a field generating electrically conductive structure within the dielectric stack; and attaching a heterogenous structure to the integrated photonics structure, the heterogenous structure having field sensitive material that is sensitive to a field generated by the field generating electrically conductive structure.

There is set forth herein an integrated photonics structure having a waveguide disposed within a dielectric stack of the integrated photonics structure, wherein the integrated photonics structure further includes a field generating electrically conductive structure disposed within the dielectric stack; and a heterogenous structure attached to the integrated photonics structure, the heterogenous structure having field sensitive material that is sensitive to a field generated by the field generating electrically conductive structure. There is set forth herein a method including fabricating an integrated photonics structure, wherein the fabricating an integrated photonics structure includes fabricating a waveguide within a dielectric stack, wherein the fabricating an integrated photonics structure further includes fabricating a field generating electrically conductive structure within the dielectric stack; and attaching a heterogenous structure to the integrated photonics structure, the heterogenous structure having field sensitive material that is sensitive to a field generated by the field generating electrically conductive structure.

A planar lightwave circuit may include a set of components. The set of components may include an input waveguide to couple to an optical communications transceiver. The set of components may include an output waveguide to couple to the optical communications transceiver. The set of components may include a common port to couple to an optical fiber. The set of components may include a first polarization beam splitter. The set of components may include a second polarization beam splitter. The set of components may include a third polarization beam splitter. The set of components may include a rotator assembly including a Faraday rotator and a quarter-wave plate.

An isolator comprises a substrate having a substrate surface; and first and second waveguides that are positioned at least partially side by side along the substrate surface. The first waveguide includes a first core, the second waveguide includes a second core, and the first and second cores are surrounded by a dielectric. The first waveguide includes first and second ends, and includes a port through which an electromagnetic wave is input and output at each of the first and second ends. The second waveguide includes a first portion extending along the first waveguide and a second portion that is not included in the first portion. The second waveguide includes a nonreciprocal member that is in contact with at least a part of the second core of the first portion, and the nonreciprocal member is in contact with at least a part of the second core of the second portion.

A nonreciprocal waveguide includes a substrate, a light propagation path, a magnetic member, an insulating layer, and a mask. The light propagation path is positioned at the substrate along a substrate surface. The magnetic member is positioned at the substrate along part of the light propagation path in a longitudinal direction. The insulating layer is positioned at the substrate and contains the light propagation path and the magnetic member. Inside the insulating layer, the mask is positioned further away than the light propagation path from the substrate. As seen from a direction perpendicular to the substrate surface, the mask overlaps at least part of the light propagation path in a width direction from a side of the light propagation path opposite to the magnetic member in the width direction. The mask is positioned in at least a range in which the magnetic member is positioned in the longitudinal direction.

The present invention provides an optical in-fiber chiral fiber isolator, capable of transmitting a signal of a predetermined optical polarization in a forward direction therethrough, while rejecting all signals traveling in a backward direction therethrough, and a method of fabrication thereof. In one exemplary embodiment, the inventive optical chiral fiber isolator includes a chiral magneto-optical fiber having a helical pitch profile, a birefringence profile, and an effective Verdet constant profile, at least a portion of which is exposed to a magnetic field of a predetermined magnetic field profile (generated by a proximal magnetic field source), where the magnetic field profile, the chiral pitch profile, the birefringence profile, and the effective Verdet constant profile are selected and configured such that the inventive isolator is capable of transmitting a signal of a predetermined optical polarization in a direction from its input end toward its output end, and to reject all signals in a direction from its output end to its input end.

The present invention is based on a two-dimensional photonic crystal where are inserted defects that originate two waveguides and one resonant cavity. An electromagnetic signal that crosses the device is confined in the interior of the defects, due to the photonic band gap associated with the periodic structure that surrounds it. Its main function is the control of the flux of an electromagnetic signal over a communication channel, blocking (state off) or allowing (state on) the passage of the signal. It also promotes the change in the propagation direction of an electromagnetic signal by an angle of 120 degrees, providing greater flexibility in the design of integrated optical systems. The working principle of the device is based on the excitation of dipole modes in its resonant cavity, accordingly to the application of an external DC magnetic field on the magneto-optical material that constitutes it. In states on and off the magneto-optical material is magnetized and nonmagnetized, respectively.