A polarization scrambler based on Faraday magneto-optic effect is disclosed. A polarization control unit (2) is connected between a first rotator unit (1) and a second rotator unit (3). The first rotator unit (1) includes a first optical fiber circle (11) and a first wire coil (12). The second rotator unit (3) includes a second optical fiber circle (31) and a second wire coil (32). ACs with two frequencies f1 and f2 are respectively introduced into the first wire coil (12) and the second wire coil (32), such that the ACs in the two wire coils are changed to control the polarization angle in the two optical fiber circles to independently change within the range of +/90. The polarization control unit (2) can ensure motion trajectories of outputted light polarization pointsare in two orthogonal directions, thus achieving uniform polarization disturbance.

Embodiments provide a polarizer and a polarization modulation system. The polarizer includes at least one MMI multi-mode waveguide, where one side of each MMI multi-mode waveguide is connected to an input waveguide, and the other side is connected to an output waveguide. An end portion of the side, on which the output waveguide is located, of the MMI multi-mode waveguide is provided with an adjustable portion, and the adjustable portion is connected to the output waveguide. The polarizer further includes a controller connected to the adjustable portion, where the controller is configured to perform control to change a material property of the adjustable portion, so that the output waveguide outputs optical signals in different polarization states.

Embodiments provide a polarizer and a polarization modulation system. The polarizer includes at least one MMI multi-mode waveguide, where one side of each MMI multi-mode waveguide is connected to an input waveguide, and the other side is connected to an output waveguide. An end portion of the side, on which the output waveguide is located, of the MMI multi-mode waveguide is provided with an adjustable portion, and the adjustable portion is connected to the output waveguide. The polarizer further includes a controller connected to the adjustable portion, where the controller is configured to perform control to change a material property of the adjustable portion, so that the output waveguide outputs optical signals in different polarization states.

A two-dimensional photonic crystal in which are inserted four waveguides and a resonant cavity. Owing to the existence of the photonic band gap, an electromagnetic signal propagating through the device is confined within the guides and the cavity and, through the adjustment of the orientation of a dipole mode generated within the cavity, is able to function in three distinct regimes. In regime 1, subjected to an external DC magnetic field +H0, it functions as a two-way divider, with isolation of the input relative to the two outputs, and, upon reversal of the field signal, it functions as an optical key. In regime 2, with the use of a DC magnetic field H0, it functions as a waveguide bender, with the input isolated from the output, and, upon reversal of the field signal, functions as an optical key. In regime 3, subject to the application of an external DC magnetic field +H1, the device functions as a three-way divider.

A compact six-port Photonic Crystal (PhC) circulator includes a hexagonal PhC branch waveguide and six waveguide ports, wherein six PhC branch waveguides respectively correspond to the six waveguide ports, and the six waveguide ports respectively are symmetrically distributed at the periphery of PhCs. One second dielectric material column is arranged at the center of the hexagonal PhC waveguide. Six identical magneto-optical material columns respectively are arranged at first adjacent positions of the second dielectric material column. Six identical third dielectric material columns respectively are arranged at second adjacent positions of the second dielectric material column. An electromagnetic signal is inputted from any one of the waveguide ports and is outputted from the next waveguide port adjacent thereto, while the remaining waveguide ports are in a signal isolated state, thus forming unidirectional circular transmission.

An optical isolator includes a polarizer for receiving an optical signal from an optical signal source, a Faraday rotator disposed on one surface of the polarizer for rotating a polarization of the optical signal output by the polarizer and outputting the same as a rotator output optical signal, and an analyzer disposed on an opposing surface of the polarizer for receiving the rotator output optical signal and for outputting at least a part thereof. The polarizer and the analyzer each include a number of spaced elongated dielectric ridges. Each dielectric ridge has a length direction extending along the one surface of the Faraday rotator, pair of spaced sides that extend away from the one surface of the Faraday rotator and a top extending between the spaced sides opposite the one surface of the Faraday rotator. Each dielectric ridge includes an electrically conductive coating on each side of the dielectric ridge.

Nonreciprocal optical transmission devices and optical apparatuses including the nonreciprocal optical transmission devices are provided. A nonreciprocal optical transmission device includes an optical input portion, an optical output portion, and an intermediate connecting portion interposed between the optical input portion and the optical output portion, and comprising optical waveguides. A complex refractive index of any one or any combination of the optical waveguides changes between the optical input portion and the optical output portion, and a transmission direction of light through the nonreciprocal optical transmission device is controlled by a change in the complex refractive index.

A microfabricated optical apparatus that includes a light source driven by a waveform, wherein the waveform is delivered to the light source by at least one through silicon via. The microfabricated optical apparatus may also include a light-sensitive receiver which generates an electrical signal in response to an optical signal. An optical source may be attached to a carrier substrate with the TOSA by a flexible connector, in order to align the optical source before affixing it permanently.

Provided a two-dimensional photonic crystal device in which are inserted three waveguides and one resonant cavity by the creation of linear and local defects. Due to the photonic band gap related to the photonic crystal, electromagnetic signals are confined to the interior of waveguides and resonant cavity. By exciting dipole modes in the resonant cavity, with orientation that depends on the intensity of the applied DC magnetic field, the present circulator device can provide the nonreciprocal transmission of signals in the clockwise and counterclockwise directions. It can fulfill the isolation function and it is fork-shaped, providing greater flexibility in the design of integrated optical communication systems.

A two-dimensional photonic crystal formed composed of a square lattice of dielectric rods immersed in air, in which are inserted, in a controlled manner, defects that originate three waveguides and one resonant cavity. The cavity is formed of a ferrite cylinder with magneto-optical properties, and by two dielectric cylinders located near to the ferrite cylinder. It has the function of transmitting electromagnetic signals in a desired direction (clockwise or counterclockwise), defined by the sign of an external DC magnetic field H.sub.0.