EP1776744A2 - Elements emetteurs de rayonnement electromagnetique et procede de production d'inversions de population dans de tels elements emetteurs - Google Patents

Elements emetteurs de rayonnement electromagnetique et procede de production d'inversions de population dans de tels elements emetteurs

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Publication number
EP1776744A2
EP1776744A2 EP05774884A EP05774884A EP1776744A2 EP 1776744 A2 EP1776744 A2 EP 1776744A2 EP 05774884 A EP05774884 A EP 05774884A EP 05774884 A EP05774884 A EP 05774884A EP 1776744 A2 EP1776744 A2 EP 1776744A2
Authority
EP
European Patent Office
Prior art keywords
exciton
excitonic
states
energy
resonance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP05774884A
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German (de)
English (en)
Inventor
Stephan W. Koch
Mackillo Kira
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Philipps Universitaet Marburg
Original Assignee
Philipps Universitaet Marburg
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Filing date
Publication date
Application filed by Philipps Universitaet Marburg filed Critical Philipps Universitaet Marburg
Publication of EP1776744A2 publication Critical patent/EP1776744A2/fr
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S1/00—Masers, i.e. devices using stimulated emission of electromagnetic radiation in the microwave range
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/30—Structure or shape of the active region; Materials used for the active region
    • H01S5/32—Structure or shape of the active region; Materials used for the active region comprising PN junctions, e.g. hetero- or double- heterostructures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/30—Structure or shape of the active region; Materials used for the active region
    • H01S5/34—Structure or shape of the active region; Materials used for the active region comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S1/00—Masers, i.e. devices using stimulated emission of electromagnetic radiation in the microwave range
    • H01S1/02—Masers, i.e. devices using stimulated emission of electromagnetic radiation in the microwave range solid
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S2302/00—Amplification / lasing wavelength
    • H01S2302/02—THz - lasers, i.e. lasers with emission in the wavelength range of typically 0.1 mm to 1 mm
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/04—Processes or apparatus for excitation, e.g. pumping, e.g. by electron beams
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/04—Processes or apparatus for excitation, e.g. pumping, e.g. by electron beams
    • H01S5/041—Optical pumping
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/10—Construction or shape of the optical resonator, e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region
    • H01S5/14—External cavity lasers

Definitions

  • the present invention relates to novel emitter elements in the form of amplifiers and lasers of electromagnetic radiation using materials or mixtures of such materials, regardless of their aggregate state, which have excitonic energy states or in which such can be formed.
  • the invention furthermore relates to a method for producing a population in exciton p states and for producing a population inversion in such excitonic energy states, and to the use of this method for operating novel emitter elements in the form of amplifiers and lasers for generating electromagnetic radiation.
  • Excitons are understood below to mean bound electron-hole pairs.
  • the binding of the two charge carriers of these excitons takes place by means of the Coulomb interaction force and the excitonic energy states are therefore described on the basis of the energy-atomic scheme of the hydrogen atom.
  • the exciton-binding energy (or binding energy) EB is understood to mean the binding energy of the 1s-exciton state. Transitions between excitonic energy states are crucial in the interaction of electromagnetic radiation, in particular in the infrared region with matter, in particular with condensed matter or with solids for describing the absorption properties of matter, in particular of solids.
  • the excitation delivers electrons from the highest filled Valenz ⁇ band into the empty conduction band, formed by a band gap energy E 9 separated by up to a few eV, by Coulomb interaction between the remaining "hole” in the valence band and electron in the conduction band a bound electron-hole pair (exciton) .
  • This provides, among other known effects, a contribution to the absorption spectrum Energy levels or the energy levels of the excitation spectrum of the excitons in the case of a semiconductor in the image representing the excitation energy E across the pulse (see FIG.
  • the binding energies fall into regions in which internal transitions between excitonic states can absorb energies in the range of terahertz waves and partly beyond that or, in the case of population inversion, also emit them.
  • the range of THz waves is generally on the scale (from low-energy to high-energy electromagnetic waves), ie from
  • Radio waves, microwaves, infrared, visible, ultraviolet, x-ray are classified in the range between microwaves and infrared range.
  • the range of terahertz waves comprises at least the frequency range from 10 ⁇ 10 to 10 ⁇ 13 Hz and thus corresponds at least to the energy range from 0.04136 to 41.36 meV or at least the wavelength range from 2,998 cm to 2,998 mm.
  • THz waves are already being used for a variety of purposes.
  • Rota tion transitions of polar molecules in the gas phase or vibrational modes of macromolecules or crystals or processes in superconductors under ⁇ be investigated.
  • THz waves DNA analysis will also be a field of application for THz waves due to the different refractive indices of single and double-stranded DNA. This would enable so-called marker-free analysis or diagnostic methods for genetic engineering.
  • Another area of application is environmental analysis, i. the detection of ver ⁇ different substances in the air or in water or in food.
  • THz waves it will also be possible to increase the quality assurance of packaged food in the production or storage (without destruction of the packaging).
  • point-by-point scanning of extended objects with THz waves in two or three dimensions also permits THz imaging (ie 2- or 3-dimen- sional imaging, THz imaging or tomography) of the objects. So succeeded an English research team by 2-dim.
  • THz waves in the context of THz tomography is also in the field of safety engineering, e.g. in the transillumination of luggage pieces possible.
  • THz waves may be used as carrier frequencies for wireless communication, e.g. mobile devices are used.
  • Bluetooth Based on the current "Bluetooth" standard with a frequency of 2.45 GHz, it will be possible in the near future to operate radio systems with 50 or 100 GHz and THz waves with 1000 GHz, which have significantly higher transmission rates than "Bluetooth " having.
  • THz or terahertz is used synonymously for the wider range of the entire frequency range, which corresponds in energy terms to the transition between two excitonic states of arbitrary materials and systems which have or can form excitonic states.
  • tunable THz sources have been developed predominantly for spectroscopic purposes, in the field of research, encompassing "free-electron” Lasers “[6],” quantum cascade lasers “[7] or sources that use the difference-frequency method for THz generation [8]. The latter method was described, for example, in Martin Hofmann et al. [9].
  • Semiconductor emitter elements are already known in the field of technology for generating radiation in the range of THz.
  • Semiconductor emitter elements are known in particular as so-called semiconductor diodes or else in semiconductor diode lasers. Their operating principle is based on the fact that in an-formed by a pn junction-active layer conduction and valence electrons, which are separated by the band gap in the energy band of the semiconductor, injected and then recombined with emission of electromagnetic radiation.
  • a semiconductor emitter element which is suitable for emission in the far-infrared spectral range.
  • the emitter element mentioned there has a first semiconductor layer system with at least one first semiconductor layer on a first conductive layer and a second semiconductor layer with quantum dots formed therein, one on the first
  • Semiconductor layer system grown second semiconductor layer system having grown on a third semiconductor layer second conductive layer and a drive element for applying voltage pulses between the first and the second conductive layer, wherein electron tunneling is prevented by the first semiconductor layer.
  • the quantum dots serve - in a known manner - to form energy spectra for the charge carriers enclosed therein.
  • Cascade lasers form two-dimensional electron systems that form at the interfaces of semiconductor heterostructures, a limitation of Electron movements to allow electronic transitions between discrete energy levels in the conduction band.
  • DE 102 17 826 A1 Mitsubishi Denki
  • two excitation laser light sources with different emission wavelengths and a non-linear wavelength conversion device are arranged such that the two optical axes of the emission direction of the two wavelengths are in the range of Conversion device overlap so that a terahertz beam (difference of the two wavelengths of the excitation laser) is emitted in a coaxial to the two axes of the optical axis.
  • sources of THz waves are known which are based on photoconductive substances. As described, for example, in DE 102 17 826 A1 (FIG.
  • No. 2,879,439 (“Production of Electromagnetic Energy”, inventor Charles H. Townes), issued Mar. 24, 1959, discloses an apparatus for generating electromagnetic energy, comprising an ensemble of oscillating particles, which are normally located in the thermal equilibrium state in at least two different discrete energy states and are able to go from one to the other state with release of energy and means for generating an unstable imbalance distribution of particles in the at least two energy states, the means for Er ⁇ generation of an unstable imbalance distribution for the emission of Magnetic energy of a frequency which corresponds to the difference between the minde ⁇ least two energy states are suitable, further comprising a vibrating, electro-magnetic circuit with a Radio Frequenzbe ⁇ rich, which corresponds to the frequency of the electro-magnetic energy and comprising means for transmitting the radiated energy in the elektro ⁇ magnetic circuit and comprising means for extracting energy from the electro-magnetic circuit.
  • the object of the present invention is therefore to specify a method for generating a population or increasing the occupation of an exciton p-state and thus also a method for generating a population inversion in excitonic states, both of which avoid the above disadvantages.
  • the further objects of the present invention are to use the emitter, which is structurally simple, also in the form of amplifiers or lasers for the emission of electromagnetic radiation in the range of the energy differences of excitonic states.
  • the first of these objects (specification of a method for easy occupation of an exciton p state) is achieved according to the invention by specifying the method according to claim 1.
  • the second of these objects (specification of a method for generating an insertion inversion between excitonic states ) is dissolved according to the invention by specifying the method according to claim 5.
  • phase relationship can be observed in the form of an optical polarization of the material, which in turn is coupled back to the exciting laser pulse via the Maxwell equations, but such coherence can generally only last for a certain time (usually a few picoseconds) In solids, especially the long-range Coulomb interaction between all electrons and holes and the interaction between charge carriers and lattice vibrations (phonons), as well as in real systems of existing disorder effects for the Decay of the pol In general, the electron and hole densities remain after such a pulse and the subsequent decay of the polarization in the excited state.
  • the selected material which is suitable for the formation of excitons is exposed to optical excitation [step 1, optical excitation, in FIG. 6], so that an optical polarization with 2 s-like symmetry is induced simple irradiation with the energy corresponding to the 2s resonance is achieved.
  • optical excitation optical excitation
  • Step 2 Coulomb scattering
  • the excitation does not have to take place exactly at the 2s resonance, but it can be detuned up to twice the exciton binding energy.
  • the mechanism does not work because a conversion of the optical excitation does not take place directly in excitons but in unbonded electrons and holes.
  • the charge carrier densities can be broken down again by spontaneous recombination of the electron-hole pairs of the material, and thus also the bound electron-hole pairs (excitons) [step 4, recombination]. Since the excitation according to the invention into the 2s state leads, with a suitable choice of the excitation intensities, only insignificantly to the occupation of the 1s state and because occupancies in the 1 s exciton state decay in a period of nano seconds, while the transition from the 2 s into the 2 p Exciton state (as described above), that is faster, ie in the range of pico to femtoseconds, a significant inversion in p-exciton states can be achieved.
  • the lattice temperature was set at about 10 K, so that only an influence of acoustic phonons is to be expected.
  • the smaller diagram inserted in Fig. 3a shows the pumping (shaded area) and the linear absorption spectrum (Fig. solid line), Eu is the 1s exciton energy.
  • the arrow shows the density at which the dynamics are represented in FIG. 2 (a).
  • the shaded area reflects the conversion efficiency without the phonon scattering.
  • FIG. 3a shows the time profile of the pump pulse, the induced optical polarization and the generated 1s and 2p exciton density.
  • FIG. 2b shows the relative proportion of excitons in different quantum states, whereby it is not surprising, according to the previous state of knowledge, that for 1s excitation the optical polarization is mainly converted into incoherent 1s excitons.
  • the fraction ⁇ nis / n is well above 90% for low computation densities n. This large proportion was to be expected since coherent and incoherent 1s excitons have an excellent energetic
  • the method according to the invention for producing a 2p or higher p-state is also suitable and according to The prior art is novel and inventive when considered as a method for simultaneously occupying s and associated p-states.
  • the justification for the novelty and the inventive step of the method is the same as for the method according to the invention for the occupation of exciton p states, since-like the aforementioned method-no method is known in which essentially one time parallel Occupancy of an s and the associated p-state is generated.
  • the methods according to the invention are the most effective when relatively sharp, spectrally well-formed excitonic resonances or excitonic energy states are present, which is the case, for example. by appropriate cooling or other, e.g. Measurements known from spectroscopy can be easily achieved.
  • FIGS. 5 a, b, c show the extent of the population inversion obtainable by the process ("THz gain vs. detuning") as a function of the "detuning" of the excitation into the 2s exciton resonance in units of EB ie the excite binding energy (i.e., the 1s exciton binding energy) of the assay system under study.
  • Fig. 5b shows the effectiveness of the generation of charge carriers as a function of detuning. This means that it is directly proportional to the absorption spectrum of the tested test system.
  • 5c shows the magnitude of the population inversion "THz gain" in arbitrary units ("arbitrary units") for the test system under investigation (quantum wire) This representation is advantageous since the absolute gain depends on things, such as the number the quantum films (in a 2D system), the excitation intensity, etc.
  • Fig. 2 the energy scheme of an exciton
  • FIG. 4 Quantum-wire when excited in the 1 s exciton resonance
  • FIG. 5 population inversion (top left), generated excitation density
  • FIG. 6 shows the level diagram of an "excitonic THz laser” or amplifier
  • FIG. 7 shows a basic structure of an "excitonic THz amplifier”
  • excitonic emitter (amplifier or laser) is used below to give a conceptual distinction to an “excitonic laser”, which according to the general understanding only supplies energies corresponding to a recombination of the excitons and, on the other hand, ei ⁇ a shorter term for a frequency range which equable energy differences of two exciton states (see definition “THz” above).
  • FIGS. 1 to 5 have already been described in the above text parts.
  • 6 shows an inventive generation of a population inversion and the laser or amplifier process in excitonic energy states.
  • Fig. 7 shows schematically the basic configuration for an excitonic THz amplifier.
  • the electromagnetic radiation to be amplified in the THz range is irradiated into the semiconductor material in the manner known from the laser semiconductor diodes, whereby the population inversion generated between the desired states then amplifies by stimulated emission of precisely the component of the irradiated radiation takes place, which corresponds to the energy difference of the generated population inversion.
  • known optical components such as lenses made of silicon can be used to then bundle the emitted radiation or to treat in a known manner on.
  • Fig. 8 shows the schematic configuration of an excitonic THz laser.
  • the "pumping power" in the form of optical energy in pulsed or cw-form is radiated in a known manner into a cavity indicated by two reflectors (eg made of aluminum or gold) To adjust the pumping power to the permeability of a Aus ⁇ coupling mirror (partially transmissive in the range of typically 2-3% or more) and on the other energy losses.
  • the cavity may also be formed by appropriately machining or coating the surfaces of the "active material” (semiconductor, etc.)
  • the dimensions of the cavity (distance of the reflectors) or distance of the surfaces of the active material are according to the desired modes or wavelengths to choose in the manner known from the laser diodes.
  • this laser can be operated in cw (continuous wave) or in pulsed mode. It is at This laser generates a population of 2p excitons [steps (1) and (2)] by pumping near the 2s resonance.
  • Suitable mirrors for the corresponding frequency range of the transitions between the exciton states can be used to build a cavity in which, given sufficient pump powers, depending on the transition times, losses of the mirrors and other ordinary light lasers known boundary conditions, a stimulated emission elektroma ⁇ gnetischer radiation of the corresponding transitions between Exzitonenzustän- according to the appropriate geometry to be selected.
  • an "excitonic THz laser” the use of semiconductors is provided as the active material for the generation of electromagnetic radiation in the region of the exciton states, due to the higher probability of the transition of a charge carrier into the Conduction band by excitation with electromagnetic radiation is the further preferred embodiment for an "excitonic THz laser" the use of direct semiconductors particularly preferred.
  • a special type of impurity arises when one atom of the host lattice is replaced by another in the same group of the periodic table.
  • nitrogen atoms on phosphorous sites in gallium phosphide (GaP.) form impurities which are referred to as "isoelectronic" and hold charge carriers as a result of modified shielding of the atomic nucleus, while the charge carriers on donors and acceptors are bonded by the Coulomb forces
  • excitons can bind to isoelectronic impurities, ie even such systems are suitable as active media for the process according to the invention and the emitter elements according to the invention ) can be used as active material for the emitter elements according to the invention.
  • nanostructured materials preferably of semiconductors, and very particularly preferably in is preferred as an active material for the generation of electromagnetic radiation in the region of exciton states In this way, sharply pronounced exciton resonances and hence higher population inversions can be achieved than with volume semiconductors.
  • cooling is provided for shifting the exciton energy, ie the exciton resonance, so that the 2 s state level is also provided is lowered, but the energy differences between the exciton conditions do not change.
  • the cooling has the effect of noise effects, e.g. generated by unwanted Gitter ⁇ vibrations to suppress.
  • a control and / or regulation is provided to increase the emission of electromagnetic energy, which keeps the laser under the "lasing" threshold for a certain period of time and then around it to exceed and - at least for a short duration - to achieve a very high stimulated emission.
  • the method according to the invention is used in an oscillator configuration, for example for establishing a time measuring system, as known to the person skilled in the art from other optical or electromagnetic systems, but at least known from US Pat. No. 2,879,439 ,
  • excitonic THz lasers can be realized by simply applying expert knowledge “excitonic THz amplifiers” and thus generally “excitonic emitter elements” (see FIG. 7), as in the art It is only necessary to ensure that, although an ex-citonic inversion, as described above, has to be produced, without the material being introduced into a cavity.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Nanotechnology (AREA)
  • Chemical & Material Sciences (AREA)
  • Biophysics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Lasers (AREA)
  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
  • Semiconductor Lasers (AREA)

Abstract

Nouveau procédé de production de populations dans des états p excitoniques et procédé de production d'inversions de populations d'excitons, c'est-à-dire entre leurs états énergétiquement discrets dans des matières dans lesquelles des excitons (paires électron-trou liées) peuvent être produits. La présente invention concerne en outre des éléments émetteurs sous forme de lasers ou d'amplificateurs ("laser THz excitonique") ou d'oscillateurs qui reposent sur l'utilisation du présent procédé pour produire ou amplifier le rayonnement électromagnétique en fonction des écarts énergétiques des états d'excitons, ou pour utiliser ledit rayonnement sous forme de mesure de temps (oscillateur).
EP05774884A 2004-07-22 2005-07-22 Elements emetteurs de rayonnement electromagnetique et procede de production d'inversions de population dans de tels elements emetteurs Withdrawn EP1776744A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102004035635A DE102004035635A1 (de) 2004-07-22 2004-07-22 Erfindung betreffend Emitterelemente elektromagnetischer Strahlung sowie Verfahren zur Erzeugung von Besetzungsinversionen in solchen Emitterelementen
PCT/DE2005/001305 WO2006010363A2 (fr) 2004-07-22 2005-07-22 Éléments émetteurs de rayonnement électromagnétique et procédé de production d'inversions de population dans de tels éléments émetteurs

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EP1776744A2 true EP1776744A2 (fr) 2007-04-25

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US (1) US20070280303A1 (fr)
EP (1) EP1776744A2 (fr)
DE (1) DE102004035635A1 (fr)
WO (1) WO2006010363A2 (fr)

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US8693368B2 (en) * 2009-07-22 2014-04-08 Hewlett-Packard Development Company, L.P. Method and system for remote identification of a network node
US20120092105A1 (en) * 2010-09-23 2012-04-19 Weinberg Medical Physics Llc Flexible methods of fabricating electromagnets and resulting electromagnet elements
US10324037B2 (en) * 2013-11-13 2019-06-18 Gustav Hudson Low energy laser spectroscopy LELS
TWI534521B (zh) * 2013-12-09 2016-05-21 國立清華大學 類相對論輻射天線系統
CA3057518A1 (fr) * 2017-03-24 2018-09-27 Macquarie University Ameliorations apportees a des lasers terahertz et a l'extraction terahertz
CN110212395B (zh) * 2019-06-21 2020-09-08 天津大学 一种实现THz波无粒子数反转光放大的方法
EP4037560B1 (fr) * 2019-09-30 2025-03-26 Gluco Tera Tech Ag Détermination non invasive des glucose
US20210098724A1 (en) * 2019-10-01 2021-04-01 Industry-University Cooperation Foundation Hanyang University Thin film transistor
CN120242327B (zh) * 2025-04-11 2025-09-19 北京智达云创科技有限公司 一种磁场发生器治疗装置

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2879439A (en) * 1958-01-28 1959-03-24 Charles H Townes Production of electromagnetic energy
US4161436A (en) * 1967-03-06 1979-07-17 Gordon Gould Method of energizing a material
JPH0745904A (ja) * 1993-07-28 1995-02-14 Nippon Telegr & Teleph Corp <Ntt> 励起子レーザ
EP0675394B1 (fr) * 1994-03-31 2001-08-01 Canon Kabushiki Kaisha Appareil photographique apte d'enregistrement d'informations concernant le traitement de tirage de clichés photographiques
JP2728200B2 (ja) * 1995-09-04 1998-03-18 広島大学長 固体テラヘルツ帯電磁波発生装置
US6373865B1 (en) * 2000-02-01 2002-04-16 John E. Nettleton Pseudo-monolithic laser with an intracavity optical parametric oscillator
JP3747319B2 (ja) * 2002-04-09 2006-02-22 独立行政法人理化学研究所 テラヘルツ波発生装置とその同調方法
DE10251824A1 (de) * 2002-11-01 2004-05-19 Technische Universität Dresden Optoelektronisches Bauelement zur Erzeugung kohärenter Strahlung im Terahertz-Frequenzbereich
US7091506B2 (en) * 2003-04-21 2006-08-15 Rensselaer Polytech Inst Semiconductor surface-field emitter for T-ray generation
US20050242287A1 (en) * 2004-04-30 2005-11-03 Hosain Hakimi Optical terahertz generator / receiver

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2006010363A2 *

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Publication number Publication date
DE102004035635A1 (de) 2006-04-06
WO2006010363A2 (fr) 2006-02-02
WO2006010363A3 (fr) 2006-08-31
US20070280303A1 (en) 2007-12-06

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