WO2018046254A1 - Antenne thz et dispositif d'envoi et/ou de réception du rayonnement thz - Google Patents

Antenne thz et dispositif d'envoi et/ou de réception du rayonnement thz Download PDF

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Publication number
WO2018046254A1
WO2018046254A1 PCT/EP2017/070643 EP2017070643W WO2018046254A1 WO 2018046254 A1 WO2018046254 A1 WO 2018046254A1 EP 2017070643 W EP2017070643 W EP 2017070643W WO 2018046254 A1 WO2018046254 A1 WO 2018046254A1
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Prior art keywords
electrodes
thz
width
electrode
antenna
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PCT/EP2017/070643
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German (de)
English (en)
Inventor
Abhishek Singh
Stephan Winnerl
Harald Schneider
Manfred Helm
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Helmholtz-Zentrum Dresden - Rossendorf E. V.
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Publication of WO2018046254A1 publication Critical patent/WO2018046254A1/fr

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
    • H01L31/09—Devices sensitive to infrared, visible or ultraviolet radiation

Definitions

  • the invention relates to a terahertz antenna, which can be used both for generating and transmitting terahertz radiation, as well as for receiving terahertz radiation.
  • the invention further relates to a device for transmitting and / or receiving terahertz radiation with such a terahertz antenna.
  • THz radiation Terahertz radiation
  • THz radiation permeates many optically opaque materials and is non-ionizing due to its low photon energy.
  • several molecules have vibrations with frequencies in the range of THz radiation, so that certain substances can be identified by means of their spectral fingerprints by means of THz radiation.
  • the absorption spectroscopy in the terahertz frequency range the analysis and the detection of certain substances. Due to its properties, THz radiation is increasingly used in various fields, e.g. in safety engineering, in industrial process monitoring, in non-destructive testing as well as in biology and medicine.
  • Terahertz radiation can be generated and / or detected by means of so-called large-area photoconductive or photoconductive THz antennas.
  • a photoconductive THz antenna has, for example, a photoconductive semiconductor substrate or a semiconductive layer arranged on a dielectric substrate, whereupon a periodic structure of identically formed and alternately arranged electrodes and counterelectrodes is provided which are each arranged at a distance from one another (see, for example, WO 2006/047 975 A1 or DE 10 2006 014 801 A1).
  • the THz antenna is irradiated with laser radiation, whereby the semiconductor substrate in the gaps (English called "gaps"), which are formed by the distances between an electrode and an adjacent counter electrode, is excited
  • the Photon energy of the exciting laser radiation larger than the electronic band gap of the Halbleitermate as, of which the semiconductor substrate is made, so that under absorption of the laser radiation in the semiconductor substrate freely movable
  • Charge carriers are formed in the form of electrons and holes.
  • excitation e.g. Laser pulses are used, e.g. temporally short laser pulses with a pulse duration below one picosecond, whereby a pulsed generation or detection of THz radiation is possible.
  • the superimposed laser radiation of two continuously emitting lasers e.g.
  • the laser radiation acts to excite the semiconductor material to produce movable electrical charge carriers and is therefore also referred to below as excitation laser radiation.
  • the electrical current flowing between the electrodes on the one hand and the counterelectrodes on the other hand is detected by means of an ammeter.
  • the mobile charge carriers generated by the excitation laser radiation move due to the electric field of the THz radiation, generating a current flow between the electrodes on the one hand and the counterelectrodes on the other hand, whereby the current flow is detected by detecting the THz radiation.
  • an electrical voltage is applied between the electrodes on the one hand and the counterelectrodes on the other hand, so that the electrodes lie at a different electrical potential than the counterelectrodes.
  • the electric fields in adjacent gaps are respectively directed in opposite directions, the THz radiation components originating from adjacent gaps are at least partially extinguished due to destructive interference in the far field. This destructive interference can for example, by preventing the generation of photogenerated charge carriers causing THz radiation in every other gap.
  • THz radiation is generated only in those gaps in which the electric field has one and the same direction, resulting in a constructive and coherent superimposition of the emitted THz radiation in the far field.
  • the prevention of the generation of photogenerated charge carriers in every other gap can be realized, for example, by placing the photoconductive material in this area by means of a shielding layer in front of the excitation laser radiation
  • the generation of photogenerated carriers can be prevented by forming the substrate non-photoconductive in this region (e.g., by keeping this region free of photoconductive material), such as, e.g. in DE 10 2006 014 801 A1.
  • the generation of photogenerated charge carriers can be prevented in every second gap by means of a lens arrangement, by means of which the excitation laser radiation, with the exception of every other gap, is directed exclusively to the gaps with the same field direction, e.g. in DE 10 2006 059 573 B3.
  • Electrode structures allow only a limited emission or
  • THz radiation or require a complex structure and thus also corresponding complex manufacturing processes.
  • Excitation laser radiation does not contribute to the generation of mobile charge carriers, but instead is reflected or absorbed by the electrode structure or the shielding layer, so that when used as a transmitting antenna, for example, only a small part of the laser excitation energy is converted into THz radiation.
  • the portion of the excitation laser radiation which effectively contributes to the generation of mobile charge carriers can be increased, for example, by a lens arrangement, this requires a complex construction of the THz antenna.
  • the THz emission or THz detection of conventional such large-area THz Antennas essentially solely on the accelerated charge carriers in the
  • the invention provides an uncomplicated design and uncomplicated
  • the invention also provides an apparatus for transmitting and / or receiving THz radiation which has such a THz antenna.
  • a THz antenna for generating and / or receiving THz radiation, e.g. of THz radiation with a frequency between 0.01 THz and 100 THz, preferably THz radiation with a frequency between 0.1 THz and 20 THz, in particular THz radiation with a frequency between 0.2 THz and 4 THz.
  • the THz antenna can thus function both as a THz transmitting antenna for generating and transmitting THz radiation and as a THz receiving antenna for receiving and detecting THz radiation.
  • the THz antenna (hereinafter also referred to as "antenna" for short) has a spatially periodic electrode arrangement
  • Electrode arrangement has a plurality of strip-shaped electrodes and a plurality of strip-shaped counterelectrodes, which are each arranged at a distance from each other to form the periodic electrode arrangement alternately and parallel to each other.
  • the periodic electrode arrangement can thus consist of the electrodes and the counterelectrodes.
  • Periodicity direction is a periodic sequence of alternatingly arranged electrodes and counterelectrodes), unless the context dictates otherwise.
  • the electrode assembly is spatially periodic along a given periodicity direction and has electrodes arranged alternately along this periodicity direction to form a sequence electrode gap-counter electrode-gap-electrode-gap-counter electrode-gap-
  • Each of the electrodes and each of the counter electrodes is strip-shaped and has a length along a predetermined longitudinal direction, a width along a predetermined transverse direction and along a predetermined width Height or thickness direction has a thickness, wherein the length is greater than the width (for example, such that the length of the electrodes or counterelectrodes at least five times, preferably at least ten times as large as the width thereof)
  • the THz antenna may e.g. as a large-area THz antenna with dimensions of e.g. 300 ⁇ x 300 ⁇ to 100 mm x 100 mm (depending on the excitation
  • Laser radiation e.g. of their NIR pulse energy
  • All electrodes and all counter electrodes are arranged parallel to each other and have the same longitudinal direction, wherein the electrodes and the counter electrodes
  • the electrodes and the counter electrodes may be arranged such that their longitudinal direction is perpendicular to the periodicity direction and their width direction is parallel to the periodicity direction
  • Main electrode are electrically connected to each other, and that all
  • Counter electrodes are electrically conductively connected to form a second main electrode.
  • the electrodes can thus be sections of a common first main electrode, the counterelectrodes can be sections a common second main electrode. It can be provided, for example, that the electrodes are formed by the finger portions of a first finger electrode and the counter electrodes are formed by the finger portions of a second finger electrode
  • Finger electrode are formed, wherein the first and the second finger electrode are arranged to form the periodic electrode arrangement interlocking.
  • each one of the electrodes and the counter electrode adjacent in a predetermined direction define a pair of electrodes. Accordingly, the electrode arrangement has a sequence of electrode pairs, wherein each of the electrode pairs consists of an electrode and a counter electrode.
  • the THz antenna has photoconductive material such that at least the electrode and the counter electrode of each pair of electrodes are interconnected by photoconductive material.
  • the THz antenna thus has a photoconductive or photoconductive section at least in the gap between the electrode and the counterelectrode of each electrode pair, and thus every other gap in the periodic electrode arrangement such that the electrode and the counter electrode of the respective electrode pair form the photoconductive section to contact.
  • the photoconductive material is a material in which by means of optical excitation movable electrical charge carriers can be generated, so that the photoconductive material is electrically conductive under optical excitation, therefore, the photoconductive material is also referred to as a photoconductive material. In the gap between the electrode and the counter electrode of each
  • Excitation laser radiation are irradiated, so that in the photoconductive material freely movable electrical charge carriers in the form of electrons and holes are generated.
  • the counterelectrode of each pair of electrodes can thus be the optical excitation of the arranged there photoconductive material, therefore, the gap between the electrode and the counter electrode of each electrode pair is also referred to as a photoactive gap or photoactive Gap.
  • the THz antenna can thus, be formed such that in the photoactive gaps, the photoconductive sections between the electrode and the counter electrode of each pair of electrodes for excitation laser radiation are accessible.
  • the THz antenna can be designed in such a way that the photoconductive sections between the electrode and the counterelectrode of each electrode pair in the photoactive gaps are at least partly exposed to the outside, so that an effective introduction of excitation laser radiation into the photoconductive material is made possible.
  • the photoconductive material may in particular be a semiconductor material.
  • the electrodes and the counter electrodes have a larger electrical
  • the photoconductive material may in particular be a semiconductor material, i. consist of electrically semiconductive material.
  • the electrodes and the counter electrodes may be made of an electrically conductive material, e.g. made of metal. Accordingly, the electrodes and counter electrodes of the periodic electrode arrangement may be e.g. be formed as metallic electrodes or counter electrodes. It can e.g. for the photoconductive material to be in the form of a layer of semiconducting material (for example in the form of a semiconductor substrate) and the electrodes and
  • Counter electrodes are designed as metallic electrodes or counter electrodes and arranged in contact with the layer of semiconducting material (for example on the layer of semiconductive material).
  • the electrodes and counter electrodes may e.g. can be formed by a metallization, but can also be realized by doping directly in the photoconductive semiconductor material.
  • the electrodes and the counterelectrodes of the periodic electrode arrangement each have a constant width such that the electrodes have a greater width than the counterelectrodes.
  • Each of the electrodes and each of the counter electrodes thus has, within the periodic electrode arrangement, a width that is constant along its longitudinal direction (ie, constant and not varying). It can be provided in particular that each of the electrodes and each of the counter electrodes is formed with a constant width along its entire length.
  • Each of the electrodes and each of the counterelectrodes is thus designed such that within the periodic electrode arrangement, the width of the electrode or counterelectrode does not change along its longitudinal direction and thus the electrode or counterelectrode in the region of the periodic
  • Electrode assembly has the same width at each length position (wherein the width denotes the extension along the width direction and transverse to the longitudinal direction of the electrodes or counter electrodes).
  • Electrode arrangement also have the electrodes a greater width than the counter electrodes.
  • Each pair of electrodes of the periodic electrode assembly thus consists of an electrode and a counter electrode, wherein the electrode is wider than the counter electrode. It can e.g. be provided that within the periodic electrode arrangement, all the electrodes have the same width and all the counter-electrodes have the same width. In particular, it can be provided that each of the electrodes within the periodic electrode arrangement has a first width and each of the counterelectrodes within the periodic electrode arrangement has a second width, wherein the first width is greater than the second width. The width of the electrodes within the periodic
  • Electrode arrangement is also referred to as electrode width
  • the width of the counter electrodes within the periodic electrode arrangement is also referred to as the counter electrode width.
  • the proportion of the THz antenna covered by the counter electrodes can be kept low, so that more space for the photoactive gaps and thus more space for the absorption of excitation laser radiation under generation of mobile charge carriers is available, thereby eg in use As a THz transmitting antenna, the proportion of laser excitation energy converted in THz radiation can be increased.
  • the performance of the THz antenna in particular the THz emission of the THz antenna, significantly depends on the width of the electrodes.
  • the electrodes can function as effective antennas for transmitting and receiving THz radiation, e.g. when used as a THz transmitting antenna, the generation of THz radiation does not rely solely on the accelerated electrical charge carriers in the photoconductive material (or on the electric dipole associated with the generation of electrons and holes and their spatial separation in the electric field between electrode and Counter electrode is accompanied), but in addition to the electric current, which is caused by means of these charge carriers in the electrodes. It has in particular turned out that it is improved for the
  • the electrodes and counterelectrodes as strip electrodes with a constant width (uniform along the longitudinal extent)
  • a uniformly high antenna effect of the electrodes is ensured along the longitudinal extent.
  • the constant width along the longitudinal extent also allows an uncomplicated structure and a simple production of
  • THz antennas according to the invention wherein the production, for example by means of optical Lithography can be done and requires no complicated and expensive electron beam lithography.
  • the THz antenna faces at least in each photoactive gap within each pair of electrodes - and thus in every other periodic gap
  • Electrode arrangement - photoconductive material wherein the THz antenna is formed such that the photoconductive material in the photoactive gaps from outside the THz antenna is irradiated to generate electrons and holes with excitation laser radiation.
  • the gaps between adjacent electrode pairs - and thus every other second gap in the periodic electrode arrangement - are also referred to as passive gaps.
  • the THz antenna is designed in such a way that, when the THz antenna is irradiated with the excitation laser radiation in the passive gaps, a (substantially) smaller number of photogenerated movable
  • Charge is generated as in the photoactive gaps, e.g. such that when irradiating the THz antenna with the excitation laser radiation in the passive gaps no free-floating charge carriers in the form of electrons and holes are generated at all. This can be realized in different, in and of itself known manner, so that only briefly will be discussed below.
  • the THz antenna also has photoconductive material in the passive gaps between adjacent pairs of electrodes. According to other embodiments, the THz antenna has no photoconductive material in the passive gaps between adjacent pairs of electrodes.
  • the THz antenna also has photoconductive material in the passive gaps between adjacent electrode pairs, and that the THz antenna has a shielding layer, by means of which the
  • the THz antenna is a (continuous) photoconductive Substrate, wherein the electrode assembly of the electrodes and
  • Counter electrodes disposed in contact on the photoconductive substrate, and wherein the gaps or areas between adjacent pairs of electrodes above the photoconductive substrate are covered by the shielding layer.
  • the shielding layer may be separated from the substrate by an electrically insulating layer
  • Shielding layer is an impermeable to the excitation laser radiation layer from which the excitation laser radiation is blocked.
  • the shielding layer may e.g. be an optically opaque layer.
  • the THz antenna may be e.g. such that the area between adjacent pairs of electrodes (i.e., the area in the passive gaps) each has a lower photoconductivity than the area between the electrode and the counterelectrode of each pair of electrodes (i.e., the area in the photoactive gaps). It can e.g. be provided that a lateral region between adjacent electrode pairs is formed non-photoconductive or non-photoconductive, e.g. by keeping this area free of photoconductive material, e.g. by providing no material at all in this area. Accordingly, it may be provided that adjacent
  • Electrode pairs are interconnected in the passive gaps by means of a material portion, this material portion having a lower photoconductivity than the photoconductive portion between the electrode and the counter electrode of each pair of electrodes, e.g. by this
  • Material section is not continuous photoconductive. It can e.g. be provided that the entire material portion consists of non-photoconductive material.
  • the THz antenna a As a further alternative it can be provided that the THz antenna a
  • Lens arrangement which is arranged and designed such that directed to the THz antenna excitation laser radiation is directed by the lens assembly alone on the photoactive gaps and away from the passive gaps.
  • the THz antenna can thus except the periodic electrode arrangement a second periodic structure or structuring, which allows the optical excitation with photogeneration of charge carriers exclusively (or at least predominantly) in the photoactive gaps - and thus in every second gap of the periodic electrode arrangement - but not in the passive gaps.
  • This second periodic structure can, as explained above, for example, a
  • Periodic arrangement of Abletikabitesen be such that the area between adjacent pairs of electrodes each by means of a
  • this second periodic structure may be a periodic modification of the photoconductive material or substrate such that the photoconductivity in the photoactive gaps is greater than in the passive gaps, the photoconductivity in the passive gaps being e.g.
  • the second periodic structure may be a lens array (e.g., a microlens array) by which the excitation laser radiation is directed solely at the photoactive gaps.
  • a main focus of the invention lies in the formation of the electrodes and counter electrodes with different widths, which will be discussed in more detail below.
  • the electrode width is at least five times as large as the counter-electrode width, preferably at least ten times as large. It can e.g. be provided that within the periodic electrode assembly, each of the electrodes has a first width and each of the counter electrodes has a second width, wherein the first width is at least five times (preferably at least ten times) of the second width.
  • the electrode width has a (constant) value of at least 10 ⁇ m, preferably of at least 30 ⁇ m, and / or that the counter-electrode width has a (constant) value of .mu.m has a maximum of 5 ⁇ , preferably of a maximum of 2 ⁇ .
  • Electrode width has a (constant) value from the range of 10 ⁇ to 70 ⁇ , preferably from the range of 20 ⁇ to 60 ⁇ , more preferably from the range of 30 ⁇ to 50 ⁇ .
  • the electrode width may e.g. 40 ⁇ amount, which has been found to be particularly effective.
  • Counterelectrode width has a (constant) value from the range of 0.2 ⁇ to 5 ⁇ , preferably from the range of 0.5 ⁇ to 2 ⁇ .
  • the THz antenna can be used e.g. be formed such that the width of the photoactive gaps and / or the width of the passive gaps has a (constant) value from the range of 1 ⁇ to 10 ⁇ . It can
  • the width of the photoactive gaps is equal to the width of the passive gaps.
  • the THz antenna can also be designed such that the photoactive gaps have a different (in particular: greater) width than the passive gaps.
  • the width of the photoactive gaps corresponds to the distance between the electrode and the counter electrode of an electrode pair, the width of the passive gaps corresponds to the distance between two adjacent
  • the aforementioned parameters enable a particularly effective generation or detection of THz radiation, the power of the THz antenna, in particular the emission of the THz transmitting antenna, with increasing electrode width up to a certain limit value of about 40 ⁇ increases and increasingly merges with larger values in saturation.
  • the antenna effect of the electrode increases, but on the other hand, the area available for the optical excitation is reduced.
  • each of the electrodes and / or each of the counterelectrodes of the periodic electrode arrangement consists at least partially (ie partially or completely) of a transparent or semitransparent electrically conductive layer, in particular of a transparent or semitransparent layer for the excitation laser radiation.
  • the transmissive layer may be formed to behave like a metallic reflector for the radiated or detected THz radiation. According to this embodiment, the electrodes and / or
  • electrodes or counterelectrodes are transparent or semitransparent, in particular for the excitation laser radiation.
  • the thickness of the respective electrode or counterelectrode is equal to the thickness of the permeable layer.
  • the electrodes and / or counterelectrodes can be designed such that in the region of the transmissive layer the excitation laser radiation can pass through the electrode or counterelectrode. Accordingly, at least a portion of the excitation laser radiation impinging on the electrodes or counter electrodes may pass therethrough and optically excite photoconductive material disposed thereunder, whereby the generation and detection of THz radiation may be further assisted.
  • the transmissive layer may, for example, be a semi-transparent metal layer or a layer of transparent, electrically conductive oxide (also referred to as TCO layer, where TCO stands for the English "transparent conductive oxide”.)
  • the TCO layer may be, for example, a layer of indium tin oxide (also referred to as ITO layer, where ITO stands for the English "indium tin oxide”) or a layer of aluminum-zinc oxide (also referred to as AZO layer, where AZO stands for the English "aluminum doped zinc oxide”) be ,
  • ITO layer also referred to as ITO layer, where ITO stands for the English "indium tin oxide”
  • AZO layer a layer of aluminum-zinc oxide
  • AZO AZO stands for the English "aluminum doped zinc oxide
  • Counter electrodes completely or partially consists of a transparent at the excitation wavelength or semitransparent layer.
  • the excitation wavelength e.g. a near-infrared wavelength, e.g. a wavelength from the range of 780 nm to 3 ⁇ .
  • the excitation wavelength e.g. a wavelength in the range of 780 nm to 820 nm (in particular a wavelength of 800 nm) or a wavelength in the range of 1500 nm to 1600 nm (in particular provided a wavelength of 1550 nm). Accordingly, it can be provided that each of the electrodes and / or each of the counterelectrodes consists wholly or partly of a layer which is transparent or semitransparent at these wavelengths.
  • the permeable layer may in particular be designed such that the
  • Intensity of the excitation laser radiation when passing through the transmissive layer is reduced by at most 50%, e.g. by not more than 25%, preferably by not more than 10%.
  • the permeable layer can also be designed as an antireflection layer or
  • an apparatus for transmitting and / or receiving THz radiation comprising (at least) a THz antenna according to any of the above-described embodiments and a laser irradiation device.
  • the laser irradiation device is arranged and configured such that from there the THz antenna under
  • the laser irradiation device is arranged and configured in such a way that the THz antenna can be used for optical excitation with laser radiation of a predetermined wavelength (also as an excitation beam). Wavelength) is irradiated, the photon energy of the
  • the THz antenna may in particular be designed such that each of the electrodes and / or each of the counter electrodes of the electrode arrangement of the THz antenna as fully explained above consists wholly or partly of a layer transparent or semitransparent at the excitation wavelength.
  • the same is provided for transmitting and / or receiving THz radiation of a predetermined peak wavelength, the width of the electrodes being 0.2 to 0.4 times the peak wavelength.
  • the peak wavelength refers to the wavelength at which the THz antenna has its maximum transmission or reception power. It can
  • the THz antenna for transmitting and / or receiving THz radiation of a predetermined wavelength also called
  • the width of the electrodes is 0.2 to 0.4 times the predetermined wavelength.
  • the electrode width thus has a (constant) value from the range of 20% to 40% of the peak wavelength or the predetermined
  • Wavelength up This allows a particularly effective generation and detection of THz radiation, in particular a particularly effective antenna effect of the electrodes.
  • Wavelength or a predetermined wavelength wherein the device (at least) a THz antenna according to one of the above
  • the electrode width is 0.2 to 0.4 times the peak wavelength or the predetermined wavelength.
  • the inverse of the laser pulse duration corresponds to the maximum THz emission frequency or limit frequency of the THz antenna when used as transmitting antenna.
  • Difference frequency is called, when used as a transmitting antenna substantially the difference frequency of the THz radiation frequency of the THz antenna. The same applies to the use of the THz antenna as a receiving antenna.
  • an apparatus for transmitting and / or receiving THz radiation comprising (at least) a THz antenna according to any of the above
  • Embodiments and a laser irradiation device for optically exciting the THz antenna has. According to the present aspect, the
  • Laser irradiation device for irradiating the THz antenna formed with excitation laser radiation of two different frequencies, wherein the two frequencies of the laser radiation also referred to as a difference frequency
  • Electrode width 20% to 40% of the wavelength having electromagnetic radiation at this difference frequency (e.g., in vacuum or in air).
  • the width of the electrodes has a value that is 20% to 40% of the wavelength of electromagnetic radiation whose frequency corresponds to the (absolute) difference of the two laser frequencies.
  • an apparatus for transmitting and / or receiving THz radiation is provided, wherein the apparatus
  • Embodiments and a laser irradiation device for optically exciting the THz antenna has. According to the present aspect, the
  • Laser irradiation device for irradiating the THz antenna formed with pulsed laser radiation with laser pulses of a predetermined pulse duration, wherein the inverse of the pulse duration is referred to as a cutoff frequency.
  • Radiation frequency is about a factor of 3 to 5 smaller than the cutoff frequency, so that the optimal radiation wavelength is greater by a factor of 3 to 5 than the cutoff frequency corresponding cutoff wavelength.
  • the width of the electrodes is 60% to 200% of the wavelength having electromagnetic radiation at this cutoff frequency (eg, in vacuum or in air).
  • the electrode width has a value that is 60% to 200% of the wavelength of electromagnetic radiation whose frequency corresponds to the inverse of the pulse duration of the laser pulses.
  • the above-described devices for transmitting and / or receiving THz radiation can, in addition to the laser irradiation device, in a known manner, comprise a voltage source for biasing the electrodes and counterelectrodes (for the transmitting device) and an ammeter for detecting the electrical current flowing between the electrodes and counterelectrodes Have stream (for the receiving device), but what will not be discussed in detail here.
  • an apparatus for transmitting THz radiation comprising (at least) a THz antenna according to any one of the above-described embodiments, and a
  • Voltage source for applying an electrical voltage (for example, a DC electrical voltage) between the electrodes on the one hand and the counter electrodes on the other.
  • the voltage source is connected to the electrode arrangement and designed to apply a voltage between the electrodes and the counterelectrodes such that the electrodes lie at a different electrical potential than the counterelectrodes (all the electrodes at a common first electrical potential and all counterelectrodes at a common second electrical potential).
  • Finger electrode may e.g. the first main electrode with the first pole of
  • the voltage source can be designed, for example, to provide a DC voltage and to apply the DC voltage between the electrodes on the one hand and the counterelectrodes on the other hand.
  • Rectangular voltage and applying the square wave voltage between the electrodes on the one hand and the counter electrodes on the other hand be formed.
  • a square wave voltage e.g. their modulation serve as a reference for a lock-in detection
  • in addition can be achieved (in particular when operating with amplified lasers with 1 - 300 kHz pulse repetition frequency) a reduction of the power dissipated due to the dark current ineffective performance.
  • the voltage source is for opposite polarity biasing of the electrodes and
  • the (wider) electrodes are connected to the positive pole of the voltage source and the (narrower) counter-electrodes are connected to the negative pole of the voltage source, so that the electrodes act as an anode and the counter-electrodes as the cathode.
  • the (wider) electrodes are connected to the negative pole of the voltage source and the (narrower) counterelectrodes are connected to the positive pole of the voltage source, so that the electrodes act as cathode and the counterelectrodes as anode.
  • the photoconductive material may be a semiconductor material.
  • GaAs gallium arsenide
  • Due to its properties (high electron mobility, high resistance, high breakdown field strength) GaAs is well suited for operation with high electric fields.
  • THz antenna THz field strength, THz bandwidth
  • SI-GaAs semi-insulating GaAs
  • LT-GaAs low temperature grown GaAs
  • LT GaAs it is also possible to use GaAs that has been subjected to ion bombardment to form short ones
  • GaAs is well suited for excitation with a titanium: sapphire laser (wavelength 800 nm).
  • fiber optics operating at a wavelength of 1550 nm come into consideration for the optical excitation of the photoconductive THz antenna, in particular because they are compact and inexpensive and can be operated in a straightforward manner.
  • a wavelength of 1550 nm requires photoconductive materials or
  • Photoconductive material in this case may e.g. Indium gallium arsenide (InGaAs), indium arsenide (InAs), or germanium.
  • InGaAs Indium gallium arsenide
  • InAs indium arsenide
  • germanium germanium
  • the photoconductive material is a semiconductor material whose electron mobility is different (i.e., greater or lesser) than its hole mobility. According to the present embodiment, in the case that the electron mobility is larger than the hole mobility, the
  • Voltage source is formed and connected to the electrode assembly, that from her (the (wider) electrodes are subjected to a higher electrical potential than the (narrower) counter electrodes.
  • the voltage source is formed and connected to the electrode assembly such that it applies a lower electric potential to the (wider) electrodes than the (narrower) ones.
  • the THz antenna can be designed such that the electron mobility and the hole mobility increase by a factor of at least 5 (five), preferably by a factor of at least 10 (ten).
  • Upon irradiation with the excitation laser radiation are in the semiconductor material generates movable electrical charge carriers in the form of electrons and holes, wherein the electrons may have a different mobility than the holes.
  • the electrons may have a different mobility than the holes.
  • the electrons have a greater mobility than the holes, the electrodes connected to the positive pole and the counter electrodes to the negative pole of the voltage source.
  • the electrodes are connected to the negative pole and the counter electrodes are connected to the positive pole of the voltage source.
  • THz radiation or THz detection can be further improved.
  • the devices for transmitting THz radiation described above can, in addition to the voltage source, in a known manner
  • Laser irradiation device for irradiating and optically exciting the THz antenna to generate movable electrical charge carriers in the
  • the THz antenna may e.g. be formed such that the periodic
  • Electrode arrangement with the electrodes and the counter electrodes covers an area of 1 mm 2 to 1000 mm 2 .
  • Figure 1 shows an apparatus for generating and transmitting THz radiation with a THz antenna according to an embodiment in plan view
  • Figure 2 is a cross-sectional view of the THz antenna of Figure 1 with optical excitation.
  • Figures 1 and 2 show a device 1 for generating and transmitting THz radiation with a THz antenna 3 according to one embodiment.
  • the device 1 is also referred to as THz transmitter 1 or THz radiation source 1.
  • the THz radiation source 1 has the THz antenna 3, a voltage source 5, and a laser irradiation device 7.
  • Figure 1 shows the THz antenna 3 in a schematic plan view together with the voltage source 5.
  • Figure 2 shows the THz antenna 3 in a schematic cross section together with the
  • the THz antenna 3 has a periodic electrode arrangement of a plurality of strip-shaped electrodes 9 and a plurality of strip-shaped counter electrodes 11.
  • the THz antenna 3 also has photoconductive material in the form of a
  • the semiconductor substrate 13 is electrically semiconductive and is exemplified by gallium arsenide (GaAs).
  • GaAs gallium arsenide
  • the electrodes 9 and the counter electrodes 11 are electrically conductive and in the present case are made of metal as an example.
  • the electrodes 9 and the counter electrodes 11 are in contact with the
  • the electrodes 9 and the counter electrodes 11 are each arranged at a distance from each other to form the periodic electrode arrangement alternately and parallel to each other. According to Figures 1 and 2, the runs
  • each electrode 9 and each counter electrode 11 Lengthwise direction of each electrode 9 and each counter electrode 11 along the y direction, the width direction of each electrode 9 and each counter electrode 11 along the x direction, and the thickness direction of each electrode 9 and each counter electrode 11 along the z direction Direction of the xyz coordinate system shown in the figures.
  • the electrode assembly is along a
  • Periodic direction spatially periodically, wherein the periodicity direction is given here by the x-direction.
  • Transverse direction of the electrodes 9 and counter electrodes 11 is parallel to the periodicity direction.
  • the electrodes 9 and counter electrodes 11 are
  • Electrode arrangement are arranged interdigitated.
  • the electrode arrangement thus consists, for example, of four electrodes 9 and four counterelectrodes 11, which are arranged alternately four electrode pairs 19 arranged successively along the periodicity direction.
  • the electrode 9 and the counterelectrode 11 of each electrode pair 19 are thus connected by means of an intervening section of the photoconductive
  • Each of the electrodes 9 and each of the counter electrodes 11 has a constant width.
  • each of the electrodes 9 is formed with a first width b E and each of the counter electrodes 11 is formed with a second width bG.
  • Each of the electrodes 9 is thus formed such that the width bG of the electrode 9 does not vary along the longitudinal direction of the electrode 9 given by the y-direction (the same applies to the counterelectrodes 11).
  • the width denotes the extent of the electrodes or counterelectrodes along their width direction (x-direction) and the length denotes the extent of the electrodes or counterelectrodes along their longitudinal direction (y-direction).
  • the THz antenna 3 is designed as an example such that the electrode width b E is at least five times the counter electrode width bG (b E ⁇ 5 bG). It may be provided in particular that the electrode width b E has a value of at least 10 ⁇ (eg a value of 10 ⁇ to 70 ⁇ , preferably from 20 ⁇ to 60 ⁇ , more preferably from 30 ⁇ to 50 ⁇ ) and the Jacobelektroden- width bG has a maximum value of 5 ⁇ (eg, a value of 0.2 ⁇ to 5 ⁇ , preferably from 0.5 ⁇ to 2 ⁇ ).
  • the laser irradiation device 7 is arranged and designed in such a way that the THz antenna 3 can be irradiated by it with excitation laser radiation 25 such that an optical excitation occurs in those areas in which the excitation laser radiation 25 impinges on the photoconductive semiconductor substrate 13
  • Counter electrode 11 of an electrode pair 19 are each referred to as a photoactive gap 21, the gaps between adjacent electrode pairs 19 are each referred to as a passive gap 23.
  • the width gA of the photoactive gaps 21 and the width gp of the passive gaps 23 can each have, for example, a value from the range of 1 ⁇ m to 10 ⁇ m.
  • the THz antenna 3 may be formed such that the width g A of the photoactive gaps 21 is equal to the width gp of the passive gaps 23.
  • the THz antenna 3 can also be designed such that the width g A of the photoactive gaps 21 has a different (in particular: greater) value than the width g P of the passive gaps 23.
  • the semiconductor substrate 13 is exposed to the outside, i. In this area, the surface of the semiconductor substrate 13 is uncovered, so that in this area excitation laser radiation 25 on the
  • the semiconductor substrate 13 is in each case by means of a
  • the THz antenna 3 has, as an example, a shielding layer 27 comprising a plurality of shielding layer sections, which covers the regions or gaps 23 between adjacent electrode pairs 19.
  • the THz antenna 3 has an excitation side 29 provided for the incidence of the excitation laser radiation 25, which side faces the laser irradiation device 7 during operation of the THz antenna 3.
  • the electrodes 9 and the counterelectrodes 11 are arranged on the excitation side 29 of the THz antenna 3.
  • the shielding layer 27 is arranged on the excitation side 29 of the THz antenna above the semiconductor substrate 13 in such a way that it covers the regions between adjacent electrode pairs 19 such that excitation laser radiation 25 impinging in these regions is blocked by the shielding layer 27 (eg absorbed and / or reflected).
  • no excitation laser radiation 25 can hit the semiconductor substrate 23 in the passive gaps 23, so that in the
  • Range of passive gaps 23 also no photogenerated movable
  • Shielding layer 27 is an (optically) opaque layer that is impermeable to excitation laser radiation 25.
  • the shielding layer 27 is an example of a metal layer, wherein the metallic shielding layer 27 by means of an electrically insulating insulating layer 31 of the electrodes 9 and
  • Counter electrodes 11 is separated and electrically isolated.
  • the electrodes 9 and the counter electrodes 11 may consist (partially or completely) of an optically transmissive layer, which is transparent or semitransparent for the excitation laser radiation 25, so that at least a portion of the on the Electrodes 9 and counter electrodes 11 incident excitation laser radiation 25th pass through them and can generate in the underlying areas of the semiconductor substrate 13 movable charge carriers.
  • the transmissive layer may be, for example, a semi-transparent metal layer which is semitransparent for the excitation laser radiation.
  • the transmissive layer may be, for example, an indium tin oxide layer.
  • the transmissive layer may in particular be designed such that the intensity of the excitation laser radiation during the
  • the THz radiation source 1 and the THz antenna 3 may be e.g. be provided for transmitting THz radiation with a peak wavelength of 120 ⁇ , e.g. for transmitting THz radiation of a wavelength of 120 ⁇ (which corresponds to a frequency of about 2.5 THz).
  • the electrode width bE in this case is 1/3 of the wavelength of 120 ⁇ (so that the electrode width bE is a value from the range of 0.2 to 0.4 times the peak wavelength or predetermined
  • the laser irradiation device 7 may be e.g. be designed for continuous wave excitation of the THz antenna 3 by irradiating the THz antenna 3 with excitation laser radiation 25 of two different frequencies, the two
  • the laser irradiation device 7 may be e.g. for irradiating the THz antenna with excitation laser radiation 25 of two
  • the difference of the two laser frequencies is 2.5 THz, which corresponds (in vacuum) a wavelength of about 120 ⁇ .
  • the electrode width bE of 40 ⁇ corresponds to the electrode width bE of 40 ⁇ a value of 1/3 of the wavelength of electromagnetic radiation with the
  • the laser irradiation device 7 may be configured to pulse-excite the THz antenna 3 by irradiating the THz antenna 3 with laser pulses of a predetermined laser frequency and pulse duration.
  • Laser irradiation device 7 for example, to irradiate the THz antenna with Laser pulses with a pulse duration of 100 fs be formed.
  • the inverse of the pulse duration corresponds to a cutoff frequency of 10 THz and thus a wavelength of 30 ⁇ , or an optimum radiation wavelength of 90 - 150 ⁇ .
  • the electrode width b E of 40 ⁇ thus corresponds to a value of 4/3 of the wavelength of electromagnetic radiation with the
  • the THz radiation source 1 has the voltage source 5 in addition to the laser irradiation device 7.
  • the voltage source 5 is designed to provide a direct electrical voltage.
  • the voltage source 5 is connected to the electrode arrangement such that the positive pole of the voltage source 5 is connected to the first finger electrode 15 and the negative pole of the voltage source is connected to the second finger electrode 17.
  • the wider electrodes 9 are connected to the positive pole of the voltage source 5 and function as anodes, whereas the narrower counter electrodes 11 to the negative pole of the
  • Voltage source 5 are connected and act as cathodes.
  • the electron mobility is much higher than the hole mobility. The electrode assembly is thus with the
  • Voltage source 5 is connected, that the wider electrodes 9 is connected to the electrical pole (namely the positive pole), which is attractive for the charge carriers with the larger charge carrier mobility (namely the electrons).
  • Laser irradiation device 7 irradiated with the excitation laser radiation 25, whereby in the area of the photoactive gaps 23 movable electrical
  • Charge carriers are generated in the photoconductive semiconductor substrate 13.
  • the wider electrodes 9 are also subjected to a higher electrical potential than the narrower counterelectrodes 11 by means of the voltage source 5, so that an electric field 33 directed from the electrodes 9 to the respectively adjacent counterelectrodes 11 is generated in the semiconductor substrate 13 is illustrated (in Figure 2 by means of arrows 33, wherein the direction of the arrow corresponds to the direction of the electric field).
  • the photogenerated electrons and holes in the semiconductor substrate 13 are formed by means of this electric field separated and accelerated, being generated and emitted due to the thereby caused in the (acting as metallic antennas) electrodes 9 caused electric current and due to the acceleration of the carrier THz radiation emitted. Since movable charge carriers are generated only in the photoactive gaps 23 and the electric field 33 always has one and the same direction in these gaps, constructive interference of the generated THz radiation in the far field is made possible.
  • THz antenna Although the functionality of the THz antenna has been described herein only for use as a THz transmitting antenna in connection with the THz radiation source 1, the statements apply analogously to the use of the THz antenna 3 as a THz receiving antenna.

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  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Variable-Direction Aerials And Aerial Arrays (AREA)

Abstract

L'invention concerne une antenne THz et un dispositif d'envoi et/ou de réception d'un rayonnement THz, l'antenne THz présentant plusieurs électrodes en forme de bande et plusieurs contre-électrodes en forme de bande, qui sont disposées les unes par rapport aux autres de manière alternée et parallèle en formant ainsi un ensemble d'électrodes périodique ; une électrode et une contre-électrode définissent respectivement une paire d'électrodes ; l'électrode et la contre-électrode de chaque paire d'électrodes sont reliées ensemble par des matériaux photoconducteurs ; et les électrodes et les contre-électrodes sont conçues avec une largeur constante de manière telle que les électrodes présentent une largeur supérieure à celle des contre-électrodes.
PCT/EP2017/070643 2016-09-09 2017-08-15 Antenne thz et dispositif d'envoi et/ou de réception du rayonnement thz WO2018046254A1 (fr)

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DE102016116900.5A DE102016116900B3 (de) 2016-09-09 2016-09-09 THz-Antenne und Vorrichtung zum Senden und/oder Empfangen von THz-Strahlung

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116031627A (zh) * 2023-03-28 2023-04-28 安徽大学 一种微型化超低频天线

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4696648A (en) * 1981-04-20 1987-09-29 Hughes Aircraft Company Heterostructure interdigital high speed photoconductive detector
WO2006047975A1 (fr) 2004-09-23 2006-05-11 Forschungszentrum Rossendorf E.V. Source de rayonnements tétrahertz cohérents
EP1804347A1 (fr) * 2004-09-13 2007-07-04 Kyushu Institute of Technology Élément de radiation à ondes électromagnétiques en térahertz et procédé de fabrication de celui-ci
DE102006014801A1 (de) 2006-03-29 2007-10-04 Rwth Aachen University THz-Antennen-Array, System und Verfahren zur Herstellung eines THz-Antennen-Arrays
DE102006059573B3 (de) 2006-12-16 2008-03-06 Batop Gmbh Anordnung zur Abstrahlung oder zum Empfang von Terahertz-Strahlung
JP2009105102A (ja) * 2007-10-19 2009-05-14 Panasonic Corp テラヘルツ波エミッタ装置
WO2010006440A1 (fr) * 2008-07-18 2010-01-21 T-Ray Science Inc. Antennes photoconductrices térahertz à électrodes conductrices transparentes et leurs procédés de fabrication

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4696648A (en) * 1981-04-20 1987-09-29 Hughes Aircraft Company Heterostructure interdigital high speed photoconductive detector
EP1804347A1 (fr) * 2004-09-13 2007-07-04 Kyushu Institute of Technology Élément de radiation à ondes électromagnétiques en térahertz et procédé de fabrication de celui-ci
WO2006047975A1 (fr) 2004-09-23 2006-05-11 Forschungszentrum Rossendorf E.V. Source de rayonnements tétrahertz cohérents
DE102006014801A1 (de) 2006-03-29 2007-10-04 Rwth Aachen University THz-Antennen-Array, System und Verfahren zur Herstellung eines THz-Antennen-Arrays
DE102006059573B3 (de) 2006-12-16 2008-03-06 Batop Gmbh Anordnung zur Abstrahlung oder zum Empfang von Terahertz-Strahlung
JP2009105102A (ja) * 2007-10-19 2009-05-14 Panasonic Corp テラヘルツ波エミッタ装置
WO2010006440A1 (fr) * 2008-07-18 2010-01-21 T-Ray Science Inc. Antennes photoconductrices térahertz à électrodes conductrices transparentes et leurs procédés de fabrication

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
"Perspectives in Optpelectronics", 1 November 1995, WORLD SCIENTIFIC PUBLISHING CO PTE LTD, ISBN: 978-981-0220-22-8, article X.-C. ZHANG ET AL: "Optically Generated THz Beams from Dielectrics", pages: 83 - 87, XP055417979 *
JUNYU GE ET AL: "Plasmonic photodetectors based on asymmetric nanogap electrodes", APPLIED PHYSICS EXPRESS, vol. 9, no. 8, 14 July 2016 (2016-07-14), JP, pages 084101, XP055417618, ISSN: 1882-0778, DOI: 10.7567/APEX.9.084101 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116031627A (zh) * 2023-03-28 2023-04-28 安徽大学 一种微型化超低频天线
CN116031627B (zh) * 2023-03-28 2023-06-16 安徽大学 一种微型化超低频天线
US11901617B1 (en) 2023-03-28 2024-02-13 Anhui University Miniaturized ultra-low frequency antenna

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