Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Aixtron Semiconductor Technologies Gmbh

Heinrich-Hertz-Institute Fur Nachrichtentechnik Berlin Gmbh

Helmut Roehle

Bernd Sartorius

Dennis Stanze

Roman J Dietz

Harald Kuenzel

Heinz-Gunter Bach

Roman Dietz

Werner Fabian

Klaus Biermann

Peter Wolfram

Harald KÜNZEL

The invention relates to a method for determining the relative temporal position of electromagnetic pulses. Said method having the steps generating a sequence of first electromagnetic pulses, generating a sequence of second electromagnetic pulses, overlaying at least a part of the first and the second pulses in a saturable absorber, detecting the second pulses that have passed through the saturable absorber by means of a detector in such a manner that the second pulses, but not the first pulses that have passed through the saturable absorber, are detected, and determining the temporal position of the first pulses relative to the temporal position of the second pulses with the aid of a signal from the detector which is generated when the second pulses that have passed through the saturable absorber are received.

Method for determining the relative temporal position of electromagnetic pulses and determination device

The invention relates to a method for determining a liquid in a closed container using THz radiation, in which a first and a second measurement are carried out, wherein the THz radiation is emitted in the direction of the liquid for measuring properties of the liquid, and a portion of the THz radiation coming from the direction of the liquid is detected. In the proposed method, the closed container contains, in addition to the liquid, a gas, wherein a wall of the container is transmissive for THz radiation and wherein the detected portion of the THz radiation in the first measurement is reflected at a boundary surface between the wall and the gas or a pocket containing the gas, and the second measurement is reflected at a boundary surface between the wall and the liquid. The first measurement thus serves as a reference measurement for capturing disturbing losses in the THz beam path and for determining influences of the wall on a measurement result for the second measurement. The invention further relates to an arrangement suitable for carrying out this method.

Method and apparatus for determining a substance using THz radiation

A photoconductor comprising a layer stack with a semiconductor layer photoconductive for a predetermined wavelength range between two semiconductor boundary layers with a larger band gap than the photoconductive semiconductor layer on a substrate, wherein the semiconductor boundary layers comprise deep impurities for trapping and recombining free charge carriers from the photoconductive semiconductor layer, and two electrodes connected to the photoconductive semiconductor layer, for lateral current flow between the electrodes through the photoconductive semiconductor layer.

Fast photoconductor

A material may be identified using THz radiation that simultaneously or sequentially includes at least one first frequency portion and a second frequency portion different therefrom. An object formed from the material to be identified is irradiated with the THz radiation and the THz radiation exiting the object is detected using a phase-sensitive THz receiver. A time or phase offset, caused by the object, is measured at least for the first frequency portion and a material thickness is determined therefrom. Attenuation of the received signal, at least for the second frequency portion, is determined. An absorption coefficient for at least the second frequency portion is calculated using the material thickness.

Method and device for identifying a material

A terahertz system can be configured for producing and coherently detecting terahertz radiation. The system can comprise a laser light source and two THz antennas, a first of which is used as a transmission antenna and a second of which is used as a receiver antenna, which are each optically coupled to the laser light source by an optical fiber and can be activated by light from this laser light source, wherein the THz antennas each have a semiconductor chip to which antenna conductors have been contact-connected and which comprises at least one photosensitive active layer with a band edge wavelength which is longer than a wavelength of the laser light source and at least one layer, adjoining the active layer, with a band edge wavelength which is shorter than the wavelength of the laser light source, wherein the band edge wavelength of the active layer of at least one of the THz antennas is at least 200 nm longer than the wavelength of the laser light source.

Improved-efficiency fibre-coupled terahertz system

The invention relates to a system for producing a signal having a variably adjustable time position or phase position, comprising at least one light source for producing a first light component () having a first wavelength and a second light component (') having a second wavelength deviating from the first wavelength and a phase modulator () for varying a phase of the first light component (), wherein the system is designed to produce a beat note signal by superposing the two light components (&#x2032;) and has a common optical fiber () for coupling in both light components (&#x2032;), wherein furthermore the phase modulator () is arranged at an end or in the course of said optical fiber () and is transparent to both light components (&#x2032;) and is designed to vary the phase of the first light component () selectively independently of a phase of the second light component (&#x2032;) or more intensely than the phase of the second light component (&#x2032;). The invention further relates to a use of such a system.

Arrangement for generating a signal having an adjustable time position or phase position

The present invention relates to a device for creating and coherently detecting terahertz radiation, comprising a laser light source (), a transmission antenna () that can be activated by the laser light source () for creating the terahertz radiation, and a receiver with a receiver antenna () that can be activated by the same laser light source (), wherein the transmission antenna () comprises a photo diode as a light-sensitive element and the receiver antenna () a fast photo-conductor as a light-sensitive element. The invention further relates to a use of such a device for analyzing a sample.

Method for creating and coherently detecting terahertz radiation

Time-domain measurements are carried out using arrangements and methods. A transmitter generates electro-magnetic pulses upon receipt of pulses of an optical pulse source. A coherent detector detects the electro-magnetic pulses or an evoked electro-magnetic signal. A delay line periodically changes the optical path length between the optical pulse source and the coherent detector and/or the electro-magnetic transmitter by periodically moving an optical element of the delay line. A position sensor determines the position of the optical element and smoothes the data generated by the position sensor. The coherent detector detects the electro-magnetic signal evoked by the electro-magnetic pulses. Pulses of the optical pulse source trigger the coherent detector. The time-dependency of the electro-magnetic pulses and/or of the electro-magnetic signal evoked by the electro-magnetic pulses are determined using signals of the coherent detector upon receipt of the electro-magnetic pulses and/or of the electro-magnetic signal and the smoothed position sensor data.

Method and arrangement for carrying out time-domain measurements

Disclosed is a gas inlet device comprising a gas reservoir (,), which is connected via a supply line (,) via a supply flow restrictor (,) which can be closed by a supply valve,). The gas can be supplied into the antechamber (,) via a control valve (,) and a control flow restrictor (,). As the control valve (,) and the supply valve (,) close the antechamber from the outside, there are only minimal fluctuations in pressure during switching. By this means the pressure in the antechamber (,) can be controlled precisely and the gas flow from the antechamber (,) into the supply line (,) can be set with great precision.

Gas inlet device for a coating system

Waste gases and other noxious substances which are formed in connection with chemical processes and the manufacture of devices such as semiconductors and covalent hydrides and element organic compounds, etc. are treated so as to remove the noxious components. The inventive method removes noxious components from substances including waste gases one group or part of said noxious components containing covalent hydrides and element-organic compounds and another group or part of said noxious components containing halogens, halogens in aqueous solutions, and acid compounds such as hydrogen halides and pseudohalides; which removal comprising: oxidizing noxious components of said one group or part in a first stage and a spontaneous reaction by means of one of:

Growing community of inventors

Berlin, Germany

Helmut Roehle