Techniques are described for a device that includes an optical channel configured to transport an optical signal. The device further includes a magnetic material with low optical absorption through which a portion of the optical signal is configured to flow. The magnetic material is configured to receive an electrical signal that sets a magnetization state of the magnetic material. The magnetic material is further configured to modulate, based on the magnetization state, the portion of the optical signal flowing though the magnetic material.

A Faraday rotator that simultaneously achieves substantial polarization rotation and net zero bend-induced birefringence can be made using optical fiber bent into multiple (e.g., a large number of) fiber turns extending along a common, substantially closed-loop path and surrounded by a solenoid, with the closed-loop path shaped in three dimensions to include loop sections in mutually orthogonal planes.

A Faraday rotator that simultaneously achieves substantial polarization rotation and net zero bend-induced birefringence can be made using optical fiber bent into multiple (e.g., a large number of) fiber turns extending along a common, substantially closed-loop path and surrounded by a solenoid, with the closed-loop path shaped in three dimensions to include loop sections in mutually orthogonal planes.

Methods for forming magneto-optical films for integrated photonic devices and integrated photonic devices incorporating same are described. An optical isolator or any nonreciprocal photonic component for an integrated photonic device can be fabricated by depositing a functional garnet layer directly onto a non-garnet substrate; depositing a seed garnet layer on the functional garnet layer; and after depositing both the functional garnet layer and the seed layer performing an annealing process. Since the seed garnet layer crystalizes faster than the functional garnet layer, crystallization of the functional garnet layer can be accomplished directly on the non-garnet substrate during a single annealing step for the seed layer and the functional garnet layer.

A method, apparatus and system for minimally intrusive fiber identification includes imparting a time-varying modulation onto an optical signal propagating in an optical fiber and subsequently detecting the presence of the time-varying modulation in the optical signal transmitting through the fiber to identify the fiber. In a specific embodiment of the invention, a time-varying curvature is imposed on the fiber to be identified and the presence of the resultant time variation in the transmitted power of a propagating optical signal is subsequently detected for identification of the manipulated fiber.

A method, apparatus and system for minimally intrusive fiber identification includes imparting a time-varying modulation onto an optical signal propagating in an optical fiber and subsequently detecting the presence of the time-varying modulation in the optical signal transmitting through the fiber to identify the fiber. In a specific embodiment of the invention, a time-varying curvature is imposed on the fiber to be identified and the presence of the resultant time variation in the transmitted power of a propagating optical signal is subsequently detected for identification of the manipulated fiber.

The present invention is based on a two-dimensional photonic crystal in which are inserted, in a controlled manner, defects that originate the waveguides and the resonant cavity that integrate the device. Its main function is to provide the control of the passage of an electromagnetic signal over a communications channel, blocking (state off) or allowing (state on) the passage of the signal. It also has the function of changing the propagation direction of an electromagnetic signal by an angle of 60 degrees, offering greater flexibility in the design of integrated optical systems. The operating principle of the device is associated with the excitation of dipole modes in the resonant cavity, which is based on a magneto-optical material. When the switch is under the influence of an external DC magnetic field H.sub.0, a rotating dipole mode excited in the cavity allows the passage of the input signal to the output (state on), whereas without the application of H.sub.0, a stationary dipole mode excited in the cavity, with the nodes aligned to the output waveguide, prevents the passage of the input signal to the output (state off).

Methods for forming magneto-optical films for integrated photonic devices and integrated photonic devices incorporating same are described. An optical isolator or any nonreciprocal photonic component for an integrated photonic device can be fabricated by depositing a functional garnet layer directly onto a non-garnet substrate; depositing a seed garnet layer on the functional garnet layer; and after depositing both the functional garnet layer and the seed layer performing an annealing process. Since the seed garnet layer crystalizes faster than the functional garnet layer, crystallization of the functional garnet layer can be accomplished directly on the non-garnet substrate during a single annealing step for the seed layer and the functional garnet layer.

A broadband three-port optical circulator having introduced therein a triangular guide column, comprising two-dimensional triangular lattice photonic crystals constituted by first medium material columns in a low refractive index background medium and three corresponding ports provided with three photonic crystal branch waveguide and distributed at the periphery of the photonic crystals. One second medium material column is arranged at the center at where the three photonic crystal branch waveguide converge, three identical magneto-optical material columns respectively are arranged around the second medium material column, the three magneto-optical material columns are in a rotationally symmetrical distribution at 120 around the center at where the three branch waveguide intersect, and each of the magneto-optical material columns is arranged on the axis of the branch waveguide at where each is located. An electromagnetic signal is inputted from any one port and is outputted from the adjacent port adjacent thereto, while the other port is in an isolated state, thus allowing unidirectional optical circulator transmission. The optical circulator is structurally compact and easy to assemble.

An integrable, non-reciprocal optical component, with guidance, between two magneto-plasmonic interfaces each formed between a dielectric and a metal. An optical port and an input signal passes through a selection region providing a selected signal whose energy is concentrated in a single plasmonic mode, LRSPP or SRSPP, by a selection aperture of a width for which these modes have optical impedances that differ significantly from each other, one of which (z1eff) is close to, or equal to, the input optical impedance (z0eff). The selected signal passes through a differentiation region, which enhances the asymmetry between the two magneto-plasmonic interfaces, to concentrate its energy on a single magneto-plasmonic interface. The differentiated signal passes through a non-reciprocal treatment region formed by two magneto-plasmonic interfaces of non-equivalent geometries. The input signal will thus undergo different treatment from a reverse signal.