Abstract: A reliability-based topology optimization design method for a part structure considering bounded hybrid uncertainties, includes the following steps: considering the uncertainties in the manufacture and service of the part structure, describing an external load with insufficient samples and a material property with sufficient samples as an interval variable and a bounded probabilistic variable respectively; discretizing a design domain of the part structure, setting the physical and geometric constraints, and establishing a reliability-based topology optimization design model; solving by a moving asymptote algorithm: decoupling the probabilistic and interval uncertainties, and determining the worst working condition by using gradients of constraint performance functions; defining a performance fluctuation under the worst working condition and calculating reliability of constraint performance; and finally, calculating the gradients of objective and constraint functions with respect to the design variables for i

Abstract: A reliability-based topology optimization design method for a part structure considering bounded hybrid uncertainties, includes the following steps: considering the uncertainties in the manufacture and service of the part structure, describing an external load with insufficient samples and a material property with sufficient samples as an interval variable and a bounded probabilistic variable respectively; discretizing a design domain of the part structure, setting the physical and geometric constraints, and establishing a reliability-based topology optimization design model; solving by a moving asymptote algorithm: decoupling the probabilistic and interval uncertainties, and determining the worst working condition by using gradients of constraint performance functions; defining a performance fluctuation under the worst working condition and calculating reliability of constraint performance; and finally, calculating the gradients of objective and constraint functions with respect to the design variables for i

Abstract: Randomly polarized light impinges upon a birefringent crystal, is split into orthogonal polarization components and emerges from the crystal separated by a walk-off distance. The light beams then impinge on polarization rotators that cause a rotation of the plane of polarization by +45° and −45°. The light then encounters a variable polarization rotator in which the plane of polarization is rotated through a angle that varies in response to an externally-applied control signal. The maximum operating range (0 to 100% attenuation) is achieved when the variable rotator is capable of rotations in the range ±45°. A second birefringent crystal functions as a beam displacer. The beams encounter two wave plates configured to produce rotation angles of 0° and 90° followed by a retroreflector. The reverse traverse of the attenuator causes the light to emerge at an output port attenuated in intensity.

Abstract: The present invention relates to the use of magnetic materials in combination with magneto-optic materials to improve performance of Faraday rotator devices by enhancing the latching capability and reducing the driving current. Semi-hard magnetic materials are advantageously used in connection with some embodiments of the present invention. Placing such semi-hard magnetic materials in proximity with the magneto-optic material enhances latching and reduces the drive current required to cause switching. Encompassing both the magneto-optic material and the semi-hard magnetic material further reduces drive current requirements and enhances latching by reducing leakage of the magnetic field from its generation within the coil to the magneto-optic material. Some embodiments further include soft or semi-hard material encompassing the coil.

Abstract: The present invention relates to the use of magnetic materials in combination with magneto-optic materials to improve performance of Faraday rotator devices by enhancing the latching capability and reducing the driving current. Semi-hard magnetic materials are advantageously used in connection with some embodiments of the present invention. Placing such semi-hard magnetic materials in proximity with the magneto-optic material enhances latching and reduces the drive current required to cause switching. Encompassing both the magneto-optic material and the semi-hard magnetic material further reduces drive current requirements and enhances latching by reducing leakage of the magnetic field from its generation within the coil to the magneto-optic material. Some embodiments further include soft or semi-hard material encompassing the coil.

Abstract: The present invention relates to optical switches in which switching occurs by changing the rotation of the plane of polarization by application of an externally applied control signal, particularly to magneto-optical switches controlling the port by which light emerges from the switch by externally-applied magnetic fields. The switches of the present invention function for randomly polarized input light, producing similarly randomly polarized light at the appropriate output port. Specific embodiments relate to 1×2 and 1×4 switches in both single pass and dual pass embodiments. Single pass embodiments are switches in which light passes through the optical components in one direction emerging at the appropriate output port depending on the desired switching. Dual pass embodiments are switches in which the light makes a forward and reverse traverse of the switch with total reflection. Dual pass switches typically reduce crosstalk without increasing the size of the switch.

Abstract: The present invention relates to optical switches in which switching occurs by changing the rotation of the plane of polarization by means of an externally applied control signal, particularly to magneto-optical switches controlling the port by which light emerges from the switch by externally-applied magnetic fields. The switches of the present invention function for randomly polarized input light, producing similarly randomly polarized light at the appropriate output port. Specific embodiments relate to 1×2 and 1×4 switches in both single pass and dual pass embodiments. Single pass embodiments are switches in which light passes through the optical components in one direction emerging at the appropriate output port depending on the desired switching. Dual pass embodiments are switches in which the light makes a forward and reverse traverse of the switch with total reflection. Dual pass switches typically reduce crosstalk without increasing the size of the switch.

Abstract: The present invention relates to variable attenuation of an light beam by use of polarization rotators in which the degree of rotation of the polarization is determined by an externally-applied control signal leading to variable attenuation of the light beam under the control of the external signal. Randomly polarized light arrives at input port to the variable optical attenuator, encounters a birefringent crystal, is split into orthogonal polarization components and emerges from the crystal separated by a walk-off distance. The light beams then impinge on the surface of wave plates (polarization rotators) that are configured to cause a rotation of the plane of polarization by +45° and −45° rotation. Both light beams then impact a variable polarization rotator in which the plane of polarization is rotated through a angle that can be varied in response to an externally-applied control signal.