175 results about "Thz waves" patented technology

A detecting apparatus for detecting information of a liquid object or sample includes a transmission path, a THz wave supplying unit, a THz wave detecting unit, and an infiltrative holding member for infiltration and holding of a liquid object. The supplying unit supplies an electromagnetic wave in a frequency range between 30 GHz and 30 THz to the transmission path. The detecting unit detects the THz wave transmitted through the transmission path. The infiltrative holding member is set at a location containing at least a portion in which an electric field distribution of the THz wave propagating along the transmission path extends.

Electromagnetic radiation sources operating in the Terahertz (THz) region capable of overcoming the Manley-Rowe limits of known optical schemes by achieving phase matching between a THz wave and optical pulse in a nonlinear waveguide, or by achieving both phase and group velocity matching between a THz wave and optical pulse in a nonlinear waveguide to yield even higher efficiencies in converting optical power to the THz region.

In a micro-bridge structure in which a temperature detecting portion (diaphragm) including a bolometer thin film is supported by a supporting portion in a state floated from a circuit substrate, a reflective film reflecting a THz wave is formed on the circuit substrate, an absorbing film absorbing the THz wave is formed on the temperature detecting portion, and an optical resonance structure is formed by the reflective film and temperature detecting portion. A gap between the reflective film and temperature detecting portion measures approximately ¼ infrared wavelength (e.g., 1.5 to 2.5 μm). Sheet resistance of the temperature detecting portion is set in a range in which an absorptance of the THz wave becomes a predetermined value or above on the basis of the THz wave (approximately 10-100 Ω/sq.). The absorptance of the THz wave is drastically improved while using the structure and manufacturing technique of a bolometer-type infrared detector.

The invention relates to the field of metamaterial devices and provides a switching-controllable THz wave metamaterial perfect absorber (MPA) and a control method thereof. The switching-controllable THz wave metamaterial perfect absorber comprises a substrate, an MIT (metal-insulator transition) layer positioned on the substrate, a dielectric layer positioned on the MIT phase change layer and metal opening resonance units positioned on the dielectric layer and being in cyclic arrangement, and the on/off of the absorber at the resonance frequencies of the metal opening resonance units is realized through changing the conductivity of the MIT phase change layer. According to the invention, the variation of the conductivities of the MIT phase-change material before and after phase change is utilized to change the absorptivity of the absorber, so that the THz MPA can be turned on/off near the resonance frequency of the metal opening resonance units, initiative control of the electromagnetic transfer characteristics of THz wave bands at the specific frequency, and accordingly, a larger on-off ratio or modulation depth can be obtained; and the switching-controllable MPA adopting the substrate-vanadium dioxide-dielectric layer-SRRs (Split Ring Resonators) four-layer structure can control the conductivity of vanadium dioxide through an external field so as to control the absorptivity of the MPA.

The invention relates to the non linear optical frequency conversion. To realize output of high power THz wave which can be continuously tuned, and stable running at room temperature, the technical scheme used by the invention is that: a tunable terahertz radiation source based on difference frequency cherenkov effect is composed of a laser device, a frequency doubling crystal, a double wavelength parametric oscillator, a harmonic mirror, a polarization filter, a combined beam mirror, a column lens and a difference frequency crystal; the harmonic mirror is placed between the frequency doubling crystal and the double wavelength parametric oscillator; the double wavelength parametric oscillator is II type phase matching KTP (Potassium Titanyl Phosphate) crystal OPO (Optical Parametric Oscillator); the polarization filter, the combined beam mirror and the column lens are arranged between the parametric oscillator and the difference frequency crystal; the difference frequency crystal is amagnesium oxide doped lithium niobate crystal with molecular formula of MgO:LiNbO3 or MgO:LN, and the generated THz wave is coupled and output by an Si prism on the side surface of the difference frequency crystal. The tunable terahertz radiation source based on difference frequency cherenkov effect is mainly applied to the optical frequency conversion.

The invention relates to a fast scanning method based on the passive imaging of a single wave beam THz wave. Aiming at the problems of longer scanning time and overhigh system construction cost in an earlier scanning imaging method of the single beam THz wave, a rocker of a crank and rocker mechanism is adopted to drive a line scanning plane mirror to sway horizontally so as to achieve fast transverse scanning motion, and a field scanning plane mirror swaying vertically in a reciprocating way is utilized to realize longitudinal scanning motion, thereby realizing the two-dimensional scanning imaging over object space. On the premise of construction cost reduction, the invention greatly improves the scanning speed per se and simultaneously amplifies the scanning viewing field. In addition, the invention is not only suitable for the passive type THz wave single wave beam scanning imaging, but also suitable for the active type single wave beam scanning imaging of the THz wave.

A Pound-Drever-Hall frequency stabilizing system of a dual-cavity dual-frequency solid laser device comprises the dual-cavity dual-frequency solid laser device, two independent heterodyne interferometer systems, two frequency regulators and an F-P (Fabry-Perot) optical resonant cavity. The optical resonant cavity is used as frequency stabilizing reference, the two independent heterodyne interferometer systems are used for detection to obtain two channels of error signals, the two frequency regulators are driven, and two working frequencies of the dual-cavity dual-frequency solid laser device are simultaneously locked at two resonance frequencies of the F-P optical resonant cavity. The F-P optical resonant cavity is used as the frequency stabilizing reference, the two working frequencies of the dual-cavity dual-frequency solid laser device are stabilized simultaneously, the laser frequency stability is higher than 10<-10>, and the Pound-Drever-Hall frequency stabilizing system can be widely applied to fields of interferometry for absolute distances of synthesis waves, generation of THz waves and the like.

A THz radiation source comprising a dual waveguide heterostructure is provided. The dual waveguide heterostructure includes an optical waveguide contained within a larger THz waveguide layered structure. The radiation source provides a coherent guided wave of THz radiation which is generated via difference frequency mixing in a gain medium with a large second-order nonlinearity and propagated with low THz loss by a dielectric medium in the layered waveguide structure. The THz radiation source is compact, has a high power output, and may be operated in continuous-wave (CW) mode at room temperature.

The invention belongs to the technical field of terahertz wave detection, specifically discloses a terahertz wave detector, a detection system and a detection method. The terahertz wave detector comprises a lens for receiving a first optical signal and outputting a second optical signal after filtering and focusing, a detecting element for converting the second optical signal output by the lens to an electric signal to output, a signal amplifying circuit for filtering and amplifying the electric signal output by the detecting element to output, and a power supply for supplying work voltage to the detecting element and the signal amplifying circuit. The invention can detect terahertz wave to be beneficial to all terahertz wave scientific and technical research and development.

There are disclosed a nonlinear optical crystal 1 which can generate a THz wave by a parametric effect; a pump light incidence apparatus 12 for allowing a pump light 2 to be incident upon the nonlinear optical crystal; and a seed light injection apparatus 14 for injecting a seed light 5 having a variable frequency in a generation direction of an idler light 3 generated by the pump light. The seed light injection apparatus 14 comprises angle dispersion compensation means 16 set so that an incidence angle θ_IN of the seed light upon the nonlinear optical crystal 1 substantially equals to a desired phase matching condition regardless of a wavelength.

The invention discloses a free electron laser based tunable narrow-band compact terahertz radiation source. The free electron laser based tunable narrow-band compact terahertz radiation source comprises a laser source, a pulse accumulation light path, a reflecting mirror, a photocathode multi-cavity microwave electron gun, a solenoid coil and an undulator, wherein laser pulses emitted from the laser source are accumulated by n times through the pulse accumulation light path to generate a laser pulse string composed of 2n laser pulses, the laser pulse string irradiates on the surface of a negative electrode of the photocathode multi-cavity microwave electron gun by the reflecting mirror, and an electron bunch string is emitted from the surface of the negative electrode by a photoelectric effect, is accelerated by a microwave field generated by a microwave power source in a chamber of the photocathode multi-cavity microwave electron gun and enters the undulator after being transversely focused by a magnetic field of the solenoid coil so that electromagnetic radiation associated with THz waveband is stimulated. The technical scheme disclosed by the invention has the characteristics of compact structure, continuous and adjustable frequency and narrow bandwidth, and is easy to implement technically.

The invention relates to a manufacturing method for a broadband THz wave absorber unrelated to wide-angle polarization. The manufacturing method includes that semiconductor silicon with certain doping concentration is selected, a photolithography technique and an ICP (inductively coupled plasma) technique etching or a chemical corrosion technique are adopted on the surface of a silicon wafer to obtain periodically arranged grating layers with reduced reflectivity, and the rest part of the grating layers is a substrate layer with reduced transmissivity. By the arrangement, broadband absorber unrelated to the wide-angle polarization is realized in a THz band. Compared with a conventional metamaterial absorber, the high-doping silicon substrate absorber with the two-dimensional grating structure has the advantages of high absorption frequency band, unrelated to polarization, wide in incident angle and the like; the manufacturing method of the absorber is wide in material taking, simple and efficient, convenient to manufacture and wide in application range; the broadband THz absorber unrelated to the polarization can be manufactured according to actual application scenarios and demands, and absorption rate, absorption frequency band and absorption broadband can be regulated through regulation of structural parameters.

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.

The invention relates to a device for generating terahertz waves, in particular to a device for generating tunable narrowband terahertz waves by using optical difference frequency. The device comprises a pumping light source, an idler frequency light source, a nonlinear crystal and a controller. The nonlinear crystal is arranged on the light path of the co-linear beam emitted by the pumping light source and the idler frequency light source. The controller is connected with the idler frequency light source and the nonlinear crystal respectively. In order to solve the technical problem of generating THz radiation by using optical means in the background technology, the invention provides the device for generating tunable narrowband terahertz waves by using optical difference frequency. The device with simple and compact structure is operated and debugged easily. The narrowband THz waves are output quickly and continuously, and are tunable; and the output stability of the THz waves is high.

The invention relates to a method for continuously regulating central frequency and spectrum width of THz (terahertz) wave. A bundle of ultrafast laser pulse passes through a movable birefringence crystal oblique split pair and a zero-order quarter wave plate to generate a novel specially-polarized light field by a polarizing gate method. The novel light field passes through a polarizer to obtain laser pulse with width of narrow pulse with linear polarization. Laser pulses different in width are obtained by controlling inserting quantity of the birefringence crystal oblique split pair, and accordingly the function of regulating central frequency and spectrum width of the THz wave is achieved. A device is simple and easy to operate, the width of the novel laser pulse can be changed only two crystals of the birefringence crystal oblique split pair simultaneously move oppositely at equal distance, and accordingly the central frequency and the spectrum width are adjusted. The method is suitable for light sources of various pulse widths and wavelengths.

Provided are an apparatus for generating/detecting terahertz wave and a method of manufacturing the same. The apparatus includes a substrate, a photo conductive layer, a first electrode and a second electrode, and a lens. The photo conductive layer is formed on an entire surface of the substrate. The first electrode and a second electrode are formed on the photo conductive layer. The first and second electrodes are spaced from each other by a certain gap. The lens is formed on the first and second electrodes. The lens is filled in the gap between the first and second electrodes.

The invention discloses a broad-tuning waveguide terahertz radiation source. The broad-tuning waveguide terahertz radiation source comprises a laser pump source, a dual-wavelength parametric oscillator, a cylindrical lens and a panel waveguide, wherein the laser pump source outputs 532nm Q-switched pulses to the dual-wavelength parametric oscillator, the dual-wavelength parametric oscillator generates dual-wavelength pulses which are within the range, wherein the center of the range is a degeneracy point, and the radius of the range is 1064nm, the dual-wavelength pulses are focused through the cylindrical lens, and are coupled to a core layer of the panel waveguide, narrow-linewidth THz waves are generated through the second-order non-linear difference frequency effect, a THz radiation mode is generated through the Cherenkov phase matching mode, and sidewise coupling output is achieved. Due to the fact that the structure is adopted, the tuning range is expanded, broadband tuning within the range from 0.1THz to 7THz can be achieved, high-efficiency coupling of the THz waves is achieved, coherent THz radiation output with broad tuning and the narrow linewidth is finally achieved, and the broad-tuning waveguide terahertz radiation source can be widely applied to the fields such as the biomedicine imaging field, the high-resolution spectral analysis field, the material detection field and the medical diagnosis field.

[Task] To provide the THz wave generator restricting increase in manufacturing cost or large size of the entirety of the apparatus and generating efficiently the several-W THz wave.

[Means for Resolution] In a THz wave generator for generating a THz wave from a THz wave generating element by inputting a plurality of laser beams having different wavelengths to the THz wave generating element, at least one laser beam among the plurality of laser beams is formed into a pulse beam by the pulse generator and the pulse beam is amplified by an optical amplifier E and then the pulse beam is inputted to the THz wave generating element F. Preferably, the plurality of laser beams having different wavelengths are generated by inputting single wavelength beam to a multi wavelength generator from single mode laser light source and by inputting light waves having a plurality of wavelengths generated from the multi wavelength generator to wavelength selecting means.

Provided are a THz-wave generation/detection module and a device including the same, which increase heating efficiency and are miniaturized. The module includes a photomixer chip, a lens, a PCB, and a package. The photomixer chip includes an active layer, an antenna, and a plurality of electrode pads. The lens is disposed on the photomixer chip. The PCB includes a plurality of solder balls connected to the electrode pads, under the photomixer chip. The package surrounds a bottom and side of the PCB, and dissipates heating of the active layer, which is transferred from the electrode pad of the photomixer chip to the PCB, to outside.

The invention relates to a semi-conductor laser device capable of outputting double-wavelength laser for optical mixing to generate THz waves and a manufacturing method. The semi-conductor laser device comprises a semi-conductor laser device epitaxy structure formed by a substrate, a lower limiting layer I, a lower waveguide layer I, an active layer I, an upper waveguide layer I, an upper limiting layer I, a regenerating mechanism, a lower limiting layer II, a lower waveguide layer II, an active layer II, an upper waveguide layer II, current blocking layers, an upper limiting layer II and a P-type Ohm contact layer. The two current blocking layers are formed on the two sides of the longitudinal shaft of the semi-conductor laser device respectively in a wet oxidation method or a proton bombard method, and the current spreading effect of the active area II is effectively prohibited. The THz waves generated by optical mixing achieved through the double-length laser are easy to produce and achieve, light output through optical cavity coupling is coaxial, and synchronous control is achieved. The coaxial double-wavelength semi-conductor laser device enables a THz source to be simple in structure, cost is reduced, continuous output power is large, and the THz source can work at the room temperature.

The invention belongs to the technical field of electromagnetic wave polarization regulation and control and particularly relates to a broadband THz wave plate composed of a specific electromagnetic surface. The whole wave plate is manufactured on a silicon wafer substrate and composed of a bottom back scattering metal layer, a medium layer and a surface anisotropy specific medium layer. The broadband THz wave plate is a reflection-type ultra wideband THz wave plate manufactured on the basis of specific media and the specific electromagnetic surface, and the working frequency of the broadband THz wave plate ranges from 0.45 THz to 1.15 THz. With regard to plane linearly-polarized electromagnetic waves which are emitted into the broadband THz wave plate at a specific polarization angle phi within the frequency range, the reflected waves of the plane linearly-polarized electromagnetic waves can generate 90-degree polarization deflection with the efficiency exceeding 95%, and the overall energy loss is small (lower than 10%); in addition, with regard to the plane linearly-polarized electromagnetic waves which are obliquely incident at different angles theta (below 50 degrees), the effect of the broadband THz wave plate is lowered slightly, and ultrahigh polarization deflection efficiency can still be achieved within a wide frequency band range. A user can manufacture the wave plate of a corresponding structure according to the needs. Besides, the working frequency of the wave plate can be changed by zooming in or zooming out the structure dimensions in equal proportion.