80 results about "Optical rectification" patented technology

Provided are systems and methods to generate single-cycle THz pulses from a few tens of nanometers thin layer of split ring resonators (SRRs) via optical rectification of femtosecond laser pulses. The emitted THz radiation, with a spectrum ranging from about 0.1 to 4 THz, arises exclusively from pumping the magnetic-dipole resonance of SRRs around 200 THz. This resonant enhancement, together with pump polarization dependence and power scaling of the THz emission, underpins the nonlinearity from optically induced circulating currents in SRRs, with a huge effective nonlinear susceptibility of 0.8×10⁻¹⁶ m²/V that far exceeds surface nonlinearities of both thin films and bulk organic/inorganic crystals and sheet nonlinearities of non-centrosymmetric materials such as ZnTe.

A system and a method for generating terahertz (THz) radiation are provided. The system includes a photonic crystal structure comprising at least one nonlinear material that enables optical rectification. The photonic crystal structure is configured to have the suitable transverse dispersion relations and enhanced density photonic states so as to allow THz radiation to be emitted efficiently when an optical or near infrared pulse travels through the nonlinear part of the photonic crystal.

The invention relates to nonlinear optical frequency conversion, and belongs to the interdisciplinary field of the terahertz radiation source technology and the optical frequency comb technology. For providing a terahertz frequency comb device based on optical rectification in a periodically poled crystal and a modulation method, and achieving an effect that the wide spectrum output is implemented in a range of 0.2-3.5 THz, a free spectrum range can reach 0.5 THz, and the device can run stably at room temperature, the invention adopts a technical scheme as follows: the terahertz frequency comb device based on the optical rectification in a periodically poled crystal is composed of a laser device, a periodically poled crystal and a receiving/detecting system, and a beam splitter and a glass convex lens are configured between the laser device and the periodically poled crystal; a polyethylene lens is arranged between the periodically poled crystal and a detector; generated THz waves areoutputted perpendicular to the side face of the crystal, and collected by the polyethylene lens; and the receiving/detecting system comprises a photoconductive antenna detector, a computer controllerand a delay line. The device and method provided by invention are mainly applied to nonlinear optical frequency conversion.

This invention relates to a super-quick optical technology including utilizing optical non-linear conversion technology in a laser cavity to generate THz laser, and said generator utilizes a non-linear optical rectification theory to put a THz laser generator at the beam waist in the cavity to increase its laser conversion efficiency. Since a laser oscillator is used as a pump source, the THz laser generated by non-linear optical rectification has the character of wide spectrum and high repeatability.

A general approach is provided for producing devices that absorb optical photons (visible to near IR) and performs charge separation with a useful voltage between holes and electrons. These holes and electrons may be collected in electrodes for performing useful work outside the device. The described technology is generally based upon rectification of plasmons (collective electric excitations) generated by absorbing light with tuned metallic antennas. According to some embodiments, the present invention provides a spatial array of nanoscale conductors forming an optical rectenna that responds to an incident light source and generates a current offset that may be rectified by a rectification-inducing material. The present inventors foresee an extensive use of these optical rectennas as photovoltaic devices, as well as a wide interest in diverse fundamental research and applied technologies.

A signal modulation method for a receiving-end module of an induction type power supply system includes configuring a plurality of modulation periods corresponding to a modulation signal; performing modulation on a first terminal of an induction coil of the receiving-end module during the i<SP>th</SP>modulation period among the plurality of modulation periods, wherein i is an odd number; and performing modulation on a second terminal of the induction coil of the receiving-end module during the j<SP>th</SP>modulation period among the plurality of modulation periods, wherein j is an even number; wherein the second terminal does not undergo modulation when the first terminal is being modulated, and the first terminal does not undergo modulation when the second terminal is being modulated. The present invention also provides a signal rectification and modulation device.

An azeotrope separation process includes the steps: 1) adding raw materials into an extraction kettle, adding extraction agents, stirring the raw materials for a certain time, standing and separating the raw materials into a water phase and an oil phase; 2) transferring one of the water phase and the oil phase into a rectifying still, heating the raw materials by a rectifying still reboiler and enabling a vapor phase to rise into a rectifying tower; 3) condensing the vapor phase rising to the top of the rectifying tower into liquid, setting a suitable reflux ratio after total reflux stabilization, extracting over heads, then extracting products and finally extracting intermediate cut. The azeotrope separation process combines the advantages of batch rectification and extraction rectification, and is flexible in operation, good in stability, low in equipment investment and applicable to separation of a azeotropic system and a near-boiling system.

A nanoscale electron shuttle with two elastically mounted conductors positioned within a gap between conductors produces asymmetrical electron conduction between the conductors when the conductors receive an AC signal to provide for rectification, detection and/or power harvesting.

Apparatus for generating a microwave frequency comb (MFC) in the DC tunneling current of a scanning tunneling microscope (STM) by fast optical rectification, caused by nonlinearity of the DC current vs. voltage curve for the tunneling junction, of regularly-spaced, short pulses of optical radiation from a focused mode-locked, ultrafast laser, directed onto the tunneling junction, is described. Application of the MFC to high resolution dopant profiling in semiconductors is simulated. Application of the MFC to other measurements is described.

The invention relates to a method for generating and detecting terahertz pulses in real time. According to the technical scheme, the method comprises the steps that a metallic vapor vacuum arc method is carried out on lithium niobate single crystals grown through a crystal pulling method to obtain a lithium niobate single crystal sheet with copper injected, and the lithium niobate single crystal sheet is used as a terahertz radiation source (5); laser pulses generated by a titanium sapphire laser (3) enter the terahertz radiation source (5) in an incident mode, and terahertz pulses are generated through an optical rectification method; a terahertz time-domain pulse spectrum is obtained through an electro-optical sampling method, and finally fast Fourier transformation is carried out on the terahertz time-domain pulse spectrum through MatLab software installed in a computer to obtain a terahertz frequency-domain pulse spectrum. The method has the advantages that the device is simple, cost is low, the raw materials of the terahertz radiation source are rich and easy to obtain, and the terahertz pulses are high in generation efficiency.

The invention provides a thermionic triode. The thermionic triode comprises a first thermal pole, a second thermal pole and a thermal resistance regulating unit. The first thermal pole is made of a metallic material. The second thermal pole is made of a non-metallic material. The first thermal pole and the second thermal pole make close contact to form a thermal interface. The thermal resistance regulating unit is used for forming a regulation and control electric field at the thermal interface. The thermionic triode provided by the invention is simple in structure, effectively realizes thermal rectification and makes it possible to further manufacture various types of thermal logic devices.

The invention discloses an equal-scale optical rectification method for a panoramic optical image, which belongs to the fields of measurement of aviation and spaceflight images and aims at providing the equal-scale optical rectification method for the panoramic optical image by adopting pure optical rectification to directly rectify while the image is output. The equal-scale optical rectification method comprises the following rectification process that panoramic negative pieces enclose to form a circular arc shape, wherein the circle center surface of the circular arc faces to a rectification lens, and the circle center is positioned on a primary optical axis; photographic paper is in a hyperbolic curve shape; the scale of each point on the image formed on the photographic paper is identical and is the ratio the focus length to the height of the camera; an imaging light source can use a planar light source; the photographic paper is simultaneously exposed; the rectification is carried out by using different optical axial magnification powers; and the full piece is rectified into an image with the same scale as that of the optical axis. According to the equal-scale optical rectification method disclosed by the invention, the film type panoramic image is purely and optically rectified at equal scale (focus length of the camera/flying height) and a vertical image is formed after rectification. The equal-scale optical rectification method is mainly used for rectifying the negative piece image formed by a panorama camera.