130 results about "Third order nonlinear" patented technology

Servo control using ferromagnetic core material and electrical windings is based on monitoring of winding currents and voltages and inference of magnetic flux, a force indication; and magnetic gap, a position indication. Third order nonlinear servo control is split into nested control loops: a fast nonlinear first-order inner loop causing flux to track a target by varying a voltage output; and a slower almost linear second-order outer loop causing magnetic gap to track a target by controlling the flux target of the inner loop. The inner loop uses efficient switching regulation, preferably based on controlled feedback instabilities, to control voltage output. The outer loop achieves damping and accurate convergence using proportional, time-integral, and time-derivative gain terms. The time-integral feedback may be based on measured and target solenoid drive currents, adjusting the magnetic gap for force balance at the target current. Incorporation of permanent magnet material permits the target current to be zero, achieving levitation with low power, including for a monorail deriving propulsion from the levitation magnets. Linear magnetic approximations lead to the simplest controller, but nonlinear analog computation in the log domain yields a better controller with relatively few parts. When servo-controlled solenoids provide actuation of a pump piston and valves, electronic LC resonance measurements determine liquid volume and gas bubble volume.

The present invention applies microprocessing technique to utilize high refractive index of semiconductor material to prepare high quality of two-dimensional photon crystal with defect state and optical switch can be realized by utilizing high third order-nonlinear polarizability and quick response time of semiconductor material. The produced optical switch can be widely used in field of optical communication and optical computer.

A nonlinear fiber having a third-order nonlinear coefficient of at least 30 W−1km−1, and its cladding containing Er or Tm at a portion within 3 μm from the interface with its core. A wavelength conversion method of making a signal light having a wavelength λS and an intensity IS and a pump light having a wavelength λP which is shorter than 2λS and an intensity higher than IS enter a nonlinear fiber 1, and generating a converted light having a wavelength λC of λSλP / (2λS−λP) and an intensity IC by four wave mixing, wherein Er or Tm is present in the cladding at a portion with a diameter in the nonlinear fiber 1 of at most the mode field diameter, and the converted light is generated by four wave mixing while Er or Tm is excited by an excitation light.

Apparatuses and methods for supercontinuum generation using a laser beam and a plurality of condensed state transparent plates are presented. As an example, plate material to be used for one of the plurality of plates is determined. A thickness of the one of the plurality of plates is also determined. An allowable laser intensity of the laser beam is then determined to be λ / (2n0n2L), where λ is the central incident wavelength in vacuum, n0 is the linear refractive index, n2 is the third-order nonlinear coefficient. A location of a next plate is then determined to be a distance downstream from the one of the plurality of plates where a laser intensity of the laser beam returns to a value of the determined allowable laser intensity.

The invention discloses a method for inhibiting intermodulation distortion of a microwave photonic system based on carrier band processing. The method comprises a step S1 of establishing a modulation model of the microwave photonic system, a step S2 of analyzing the origin of third-order nonlinear intermodulation distortion to obtain three major intermodulation distortion components, and simultaneously, determining the relation between a carrier band phase shift amount theta and the major intermodulation distortion components, and a step S3 of adjusting the phase shift amount of the carrier band phase to theta so that the three major intermodulation distortion components obtained in the step S1 are cancelled out mutually. The invention also discloses a system for inhibiting intermodulation distortion of the microwave photonic system based on carrier band processing; the system comprises a continuous light source, a polarization control circuit, an intensity modulator, a carrier band processor and a double-tone radial frequency signal generation source. The method and the system have the advantages that no extra distortion needs to be established and the structure is simple, the inhibition of distortion can be completely only by introducing the relatively fixed carrier band phase shift amount, the performance is reliable and stable, and in addition, the advantages of an integrated device can be integrated and the integrated device is taken as the carrier band processor so that the cost can be reduced.

A method and a system method for generating optical multipartite quantum states, comprising generating optical fields by at least two different spontaneous four-wave mixing processes and overlapping the optical fields spontaneously generated from the different spontaneous four-wave mixing processes into a same resonator mode of a third-order nonlinear resonator. The system comprises a multi-colored laser source exiting a nonlinear third-order resonator at different resonance frequencies belonging to different mode families of the resonator.