摘要:
A fiber optic switch based on the magneto-optic effect of magnetic materials is presented. Due to the optical fiber based construction of the switching device it is suitable for optical fiber networks The on-off function of the switch is useful for isolation and connection of node(s) from a fiber optical network without having to turn off a laser. The switch is based on the Faraday Effect exhibited by magneto-optic materials. The all-fiber magneto-optic switch has a beam splitter at the input that splits an incoming signal into orthogonal polarized paths. Each path has at least one magneto-optic Faraday rotator (MOFR) controlled by a field. When the field is present, the polarization of the optical beam changes, thereby turning the switch on or off depending on the initial polarization of the beam. A beam coupler couples the orthogonal polarized paths at the output of the all-fiber magneto-optic switch. The MOFR is a bismuth substituted iron garnet. In an alternate embodiment the switch is constructed in the Mach-Zehnder configuration, utilizing two 3 dB couplers, isolators and MOFRs. In an alternate embodiment the switch is fabricated on silicon-on-insulator.
摘要:
Methods and apparatus or systems for providing security based on innate characteristics of devices are disclosed. A method of providing security associated with communications from a digital device includes observing an analog signal associated with communications from the digital device, characterizing the digital device at least partially based on the analog signal, and providing a security feature at least partially based on the step of characterizing.
摘要:
A fiber-based, magneto-optic (MO) optical modulator or switch based on Sagnac interferometry is provided. The system uses a magneto-optic Faraday rotator (MOFR) to produce optical modulation with low magnetic fields. The Sagnac geometry allows for increased modulation at lower fields than traditional MO modulators. This switch uses the MOFR to create different states of polarization in counter-propagating waves, which results in interference at the output port. A magnetic field is used to control the amount of rotation in the state of polarization (SOP), and therefore, the ON-OFF extinction ratio.
摘要:
A pre-pulsed magnetic field generation circuit for a fiber-based, magneto-optic (MO) optical modulator or switch for use in an interferometer is provided. The pre-pulsed magnetic field is used to control the amount of rotation in the state of polarization (SOP), and therefore, the ON-OFF extinction ratio. The circuit includes a pair of amplifier circuits that control the current through a coil to generate the pre-pulsed magnetic field. One amplifier controls a magnitude of a steady state portion of the magnetic field, while the other controls both the amplitude and duration of a pre-pulse portion of the magnetic field.
摘要:
An integrated fiber optic switch based on the magneto-optic effect of magnetic materials suitable for optical fiber networks is presented. The switch is based on the Faraday Effect exhibited by magneto-optic materials. The all-fiber magneto-optic switch has a beam splitter at the input that splits an incoming signal into orthogonal polarized paths. Each path has at least one magneto-optic Faraday rotator (MOFR) controlled by a field. When the field is present, the polarization of the optical beam changes, thereby turning the switch on or off. A beam coupler couples the orthogonal polarized paths at the output of the all-fiber magneto-optic switch. The switch is constructed in the Mach-Zehnder configuration, utilizing two 3 dB couplers, isolators and MOFRs fabricated on silicon-on-insulator.
摘要:
Methods and apparatus or systems for providing security based on innate characteristics of devices are disclosed. A method of providing security associated with communications from a digital device includes observing an analog signal associated with communications from the digital device, characterizing the digital device at least partially based on the analog signal, and providing a security feature at least partially based on the step of characterizing.
摘要:
A system and method for altering the properties of a material by exposure of the material to a magnetic field is described herein. The method comprises generating a magnetic field; exposing a material to the magnetic field, and determining the optimum settings of the magnetic field parameters for the particular material. The magnetic field may be time varying or time invariant. Various properties of the magnetic field can be altered to determine the optimum settings for altering the material properties, including the amplitude, frequency, and waveform. In one embodiment, a method for improving the conductivity of a transmission line is provided, comprising: providing a high voltage electrical transmission line; temporarily installing a magnetic field generator along at least a portion of the transmission line; and generating a pulsed magnetic field around at least a portion of the transmission line using the magnetic field generator and simultaneously running a current through the transmission line.
摘要:
A fiber-based, magneto-optic (MO) optical modulator or switch based on Sagnac interferometry is provided. The system uses a magneto-optic Faraday rotator (MOFR) to produce optical modulation with low magnetic fields. The Sagnac geometry allows for increased modulation at lower fields than traditional MO modulators. This switch uses the MOFR to create different states of polarization in counter-propagating waves, which results in interference at the output port. A magnetic field is used to control the amount of rotation in the state of polarization (SOP), and therefore, the ON-OFF extinction ratio.
摘要:
A system and method for altering the properties of a material by exposure of the material to a magnetic field is described herein. The method comprises generating a magnetic field; exposing a material to the magnetic field, and determining the optimum settings of the magnetic field parameters for the particular material. The magnetic field may be time varying or time invariant. Various properties of the magnetic field can be altered to determine the optimum settings for altering the material properties, including the amplitude, frequency, and waveform. In one embodiment, a method for improving the conductivity of a transmission line is provided, comprising: providing a high voltage electrical transmission line; temporarily installing a magnetic field generator along at least a portion of the transmission line; and generating a pulsed magnetic field around at least a portion of the transmission line using the magnetic field generator and simultaneously running a current through the transmission line.