An optical diode (1) comprising an optical wave guide for guiding light, preferably of a light mode, with a vacuum wavelength λ.sub.0, wherein the optical wave guide has a wave guide core (2, 3, 14) with a first index of refraction (n.sub.1), and the wave guide core (2, 3, 14) is surrounded by at least one second optical medium which has at least one second index of refraction (n2), wherein n.sub.1>n.sub.2 applies, wherein the wave guide core (2, 3, 14) has at least in sections a smallest lateral dimension (7) which is a smallest dimension of a cross section (6) perpendicular to a propagation direction (5) of the light in the wave guide core (2, 3, 14), wherein the smallest lateral dimension (7) is greater than or equal to λ.sub.0/(5*n.sub.1) and less than or equal to 20*λ.sub.0/n.sub.1, wherein the optical diode (1) additionally comprises at least one absorber element (10, 11, 15, 16) which is arranged in a near field, wherein the near field consists of the electromagnetic field of the light of the vacuum wavelength λ.sub.0 in the wave guide core (2, 3, 14) and outside of the wave guide core (2, 3, 14) up to a standard interval (12) of 5*λ.sub.0, wherein the standard interval (12) is measured starting from one surface (8) of the wave guide core (2, 3, 14) forming an optical interface and in a direction perpendicular to the surface (8). The invention provides that the at least one absorber element (10, 11, 15, 16) for the light of the vacuum wavelength λ.sub.0 has a strongly different absorption for left circular polarization (σ.sup.−) and the right circular polarization (σ.sup.+).

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.

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.

Magneto-optical modulator-based systems and devices for transferring quantum information are described. Such systems can be used for many applications, including as part of quantum computers. An example system includes a quantum information system configured to provide a signal corresponding to at least one qubit. The system further includes a magneto-optical driver configured to receive the signal corresponding to the at least one qubit and process the signal to generate a current based on the signal corresponding to the at least one qubit. The system further includes a magneto-optical modulator configured to receive the current from the magneto-optical driver and provide a modulated light output by modulating a received light input based on the current.

Magneto-optical modulator-based systems and devices for transferring quantum information are described. Such systems can be used for many applications, including as part of quantum computers. An example system includes a quantum information system configured to provide a signal corresponding to at least one qubit. The system further includes a magneto-optical driver configured to receive the signal corresponding to the at least one qubit and process the signal to generate a current based on the signal corresponding to the at least one qubit. The system further includes a magneto-optical modulator configured to receive the current from the magneto-optical driver and provide a modulated light output by modulating a received light input based on the current.

Systems and methods for providing a microwave-to-optical (M2O) transducer using magneto-optical field interactions with spin states of an ensemble of ions doped into a crystal structure is presented. According to one aspect, the crystal structure is a (.sup.171Yb.sup.3+:YVO) doped crystal structure that provides a substrate for an on-chip implementation of the transducer. According to one aspect, coupling of microwave and optical signals to the ions is based on respective microwave and optical waveguides fabricated in or on the doped crystal structure. According to another aspect, coupling of microwave and optical signals to the ions is based on respective microwave and optical resonant cavities fabricated in or on the doped crystal structure. Transduction can be based on either a three-level system with near-zero applied external magnetic field or on a four-level system with zero applied external magnetic field. The transducer can operate reversibly as an optical-to-microwave (O2M) transducer.

Systems and methods for providing a microwave-to-optical (M2O) transducer using magneto-optical field interactions with spin states of an ensemble of ions doped into a crystal structure is presented. According to one aspect, the crystal structure is a (.sup.171Yb.sup.3+:YVO) doped crystal structure that provides a substrate for an on-chip implementation of the transducer. According to one aspect, coupling of microwave and optical signals to the ions is based on respective microwave and optical waveguides fabricated in or on the doped crystal structure. According to another aspect, coupling of microwave and optical signals to the ions is based on respective microwave and optical resonant cavities fabricated in or on the doped crystal structure. Transduction can be based on either a three-level system with near-zero applied external magnetic field or on a four-level system with zero applied external magnetic field. The transducer can operate reversibly as an optical-to-microwave (O2M) transducer.

An optical isolator 10 according to the present disclosure includes a substrate 11 and an optical waveguide 12 provided on the substrate 11. The optical waveguide 12 includes a first end part 13, a plurality of second end parts 14 arranged in an array, and at least one branching part 18 located between the first end part 13 and the plurality of second end parts 14. The optical waveguide 12 has a portion having non-reciprocity and gives different non-reciprocal phase shift amounts between the first end part 13 and at least two of the second end parts 14.

A display device according to the present invention is a light stippling display device that performs light stippling. In the device, a plurality of hole portions are formed on a display plate portion including a magnetized sheet which is magnetized on both sides, and the hole portion is opened and closed by a light shielding body made of a magnetic ball. Thereby, the position of the light shielding body is switched between a light transmitting state and a light shielding state. The light shielding body has directivity for a center of the hole portion in the display plate portion which is magnetized on both sides in a case where the light shielding body is switched to the light shielding state. Therefore, the reliability of display can be improved, and the operability can be improved.

A display device according to the present invention is a light stippling display device that performs light stippling. In the device, a plurality of hole portions are formed on a display plate portion including a magnetized sheet which is magnetized on both sides, and the hole portion is opened and closed by a light shielding body made of a magnetic ball. Thereby, the position of the light shielding body is switched between a light transmitting state and a light shielding state. The light shielding body has directivity for a center of the hole portion in the display plate portion which is magnetized on both sides in a case where the light shielding body is switched to the light shielding state. Therefore, the reliability of display can be improved, and the operability can be improved.