Abstract: Methods and apparatus for detecting variations in electromagnetic fields, in particular, terahertz (THz) electromagnetic fields, are provided. The methods and apparatus employ polarization detection devices and controllers to maintain or vary the polarization of modulated signals as desired. The methods and apparatus are provided to characterize electromagnetic fields by directing the electromagnetic field and a probe beam upon an electro-crystal and detecting the modulation of the resulting probe beam. Detection of the modulation of the probe beam is practiced by detecting and comparing the polarization components of the modulated probe beam. Aspects of the invention may be used to analyze or detect explosives, explosive related compounds, and pharmaceuticals, among other substances. A compact apparatus, modular optical devices for use with the apparatus, sample holders, and radiation source mounts are also disclosed.

Abstract: Methods and systems for characterizing a plasma with radiation, particularly, terahertz (THz) radiation, are disclosed. The disclosed method of characterizing a plasma includes directing THz radiation into the plasma; and detecting an emission due to interaction of the THz radiation with the plasma to characterize the plasma. A disclosed plasma characterizing device includes a means for directing THz radiation into a plasma; and a detector adapted to detect an emission emitted by the plasma due to interaction of the THz radiation with the plasma to characterize the plasma. A plasma characterizing system is also disclosed. The emission detected may be a fluorescence, a variation in fluorescence and/or an acoustic emission.

Abstract: Methods and systems for detecting radiation, particularly, terahertz (THz) radiation, are disclosed. The methods and systems disclosed include directing an optical beam in a volume of gas; ionizing at least a portion of the volume of gas with the optical beam to produce a plasma; and detecting a fluorescence produced from an interaction of a radiation wave with the plasma. The information contained in the characteristics of the detected fluorescence, for example, the amplitude and/or phase are used to characterize the radiation wave. Aspects of the invention may be used for homeland security, medicine, and astronomy, among other fields.

Abstract: The present technology provides methods and compositions for the treatment of tissue-damage related immune dysregulation by administering a composition comprising one or more of CD24; CD24 fragments, variants and derivatives, CD24Fc fusion proteins; HMBG1-binding proteins, binding proteins to HMBG1 Box B; antagonists of HMGB1, polyclonal, monoclonal, recombinant, chimeric, humanized scFv antibodies and antibody fragments to HMGB1 or fragments of HMGB1 and antibodies that bind and suppress the activity of HMGB1 Box B; Siglec 10 agonists such as anti-Siglec 10 antibodies; and combinations thereof to a patient.

Abstract: Methods and systems for detecting radiation for example, terahertz radiation, with the aid of acoustic signal generation and detection include: directing an optical beam into a volume of gas; ionizing at least a portion of the volume of gas with the optical beam to produce a plasma; and detecting an acoustic signal produced from an interaction of a radiation wave with the plasma. The methods and systems are particularly adapted for remote detection of chemicals, biological substances, and explosives, among others. The capability of the methods and systems can be enhanced by employing multi-color laser excitation to produce the plasma and varying the time delay between the multi-color pulses.

Abstract: A terahertz (THz) anti-reflection device, for example, a broadband tunable THz anti-reflection device, includes a silicon substrate having a plurality of recesses, each of the plurality of recesses having a plurality of cavities of decreasing dimension. The cavities may be nested polygonal cavities, for example, having a square or rectangular cross section. The recesses having the cavities may be positioned at regular periods, for example, periods ranging from 10 ?m to 20 ?m. The devices may be fabricated by conventional lithographic methods. Also disclosed are methods for modifying terahertz radiation and methods for fabricating anti-reflection devices.

Abstract: A broadband anti-reflection apparatus for use with terahertz radiation includes a layer having an outer surface comprising a plurality of pyramid structures having about a 30 ?m to about a 110 ?m period, and wherein reflectance of the terahertz radiation is reduced compared to a layer comprising a planar outer surface. Also disclosed is a method for modifying terahertz radiation which includes receiving terahertz radiation on a device having an anti-reflection layer having an outer surface comprising a plurality of pyramid structures having about a 30 ?m to a 110 ?m period, and modifying the terahertz radiation passing through the device or processing the terahertz radiation in the device.

Abstract: Methods and systems for characterizing a plasma with radiation, particularly, terahertz (THz) radiation, are disclosed. The disclosed method of characterizing a plasma includes directing THz radiation into the plasma; and detecting an emission due to interaction of the THz radiation with the plasma to characterize the plasma. A disclosed plasma characterizing device includes a means for directing THz radiation into a plasma; and a detector adapted to detect an emission emitted by the plasma due to interaction of the THz radiation with the plasma to characterize the plasma. A plasma characterizing system is also disclosed. The emission detected may be a fluorescence, a variation in fluorescence and/or an acoustic emission.

Abstract: A method of analyzing a remotely-located object includes the step of illuminating at least a portion of a targeted object with electromagnetic radiation to induce a phase transformation in the targeted object, wherein the phase transformation produces an emitter plasma, which emits terahertz radiation. The method also includes the step of ionizing a volume of an ambient gas to produce a sensor plasma by focusing an optical probe beam in the volume and the step of detecting an optical component of resultant radiation produced from an interaction of the focused optical probe beam and the terahertz radiation in the sensor plasma. Detecting an optical component of the resultant radiation emitted by the sensor plasma facilitates detection of a characteristic fingerprint of the targeted object imposed onto the terahertz radiation produced as a result of the induced phase transformation.

Abstract: A terahertz (THz) anti-reflection device, for example, a broadband tunable THz anti-reflection device, includes a silicon substrate having a plurality of recesses, each of the plurality of recesses having a plurality of cavities of decreasing dimension. The cavities may be nested polygonal cavities, for example, having a square or rectangular cross section. The recesses having the cavities may be positioned at regular periods, for example, periods ranging from 10 ?m to 20 ?m. The devices may be fabricated by conventional lithographic methods. Also disclosed are methods for modifying terahertz radiation and methods for fabricating anti-reflection devices.

Abstract: Methods and systems for detecting radiation, particularly, terahertz (THz) radiation, are disclosed. The methods and systems disclosed include directing an optical beam in a volume of gas; ionizing at least a portion of the volume of gas with the optical beam to produce a plasma; and detecting a fluorescence produced from an interaction of a radiation wave with the plasma. The information contained in the characteristics of the detected fluorescence, for example, the amplitude and/or phase are used to characterize the radiation wave. Aspects of the invention may be used for homeland security, medicine, and astronomy, among other fields.

Abstract: A broadband anti-reflection apparatus for use with terahertz radiation includes a layer having an outer surface comprising a plurality of pyramid structures having about a 30 ?m to about a 110 ?m period, and wherein reflectance of the terahertz radiation is reduced compared to a layer comprising a planar outer surface. Also disclosed is a method for modifying terahertz radiation which includes receiving terahertz radiation on a device having an anti-reflection layer having an outer surface comprising a plurality of pyramid structures having about a 30 ?m to a 110 ?m period, and modifying the terahertz radiation passing through the device or processing the terahertz radiation in the device.

Abstract: Methods and apparatus for detecting variations in electromagnetic fields, in particular, terahertz (THz) electromagnetic fields, are provided. The methods and apparatus employ polarization detection devices and controllers to maintain or vary the polarization of modulated signals as desired. The methods and apparatus are provided to characterize electromagnetic fields by directing the electromagnetic field and a probe beam upon an electro-crystal and detecting the modulation of the resulting probe beam. Detection of the modulation of the probe beam is practiced by detecting and comparing the polarization components of the modulated probe beam. Aspects of the invention may be used to analyze or detect explosives, explosive related compounds, and pharmaceuticals, among other substances. A compact apparatus, modular optical devices for use with the apparatus, sample holders, and radiation source mounts are also disclosed.

Abstract: A method of analyzing a remotely-located object includes the step of illuminating at least a portion of a targeted object with electromagnetic radiation to induce a phase transformation in the targeted object, wherein the phase transformation produces an emitter plasma, which emits terahertz radiation. The method also includes the step of ionizing a volume of an ambient gas to produce a sensor plasma by focusing an optical probe beam in the volume and the step of detecting an optical component of resultant radiation produced from an interaction of the focused optical probe beam and the terahertz radiation in the sensor plasma. Detecting an optical component of the resultant radiation emitted by the sensor plasma facilitates detection of a characteristic fingerprint of the targeted object imposed onto the terahertz radiation produced as a result of the induced phase transformation.

Abstract: Methods and apparatus for detecting variations in electromagnetic fields, in particular, terahertz (THz) electromagnetic fields, are provided. The methods and apparatus employ polarization detection devices and controllers to maintain or vary the polarization of modulated signals as desired. The methods and apparatus are provided to characterize electromagnetic fields by directing the electromagnetic field and a probe beam upon an electro-crystal and detecting the modulation of the resulting probe beam. Detection of the modulation of the probe beam is practiced by detecting and comparing the polarization components of the modulated probe beam. Aspects of the invention may be used to analyze or detect explosives, explosive related compounds, and pharmaceuticals, among other substances. A compact apparatus, modular optical devices for use with the apparatus, sample holders, and radiation source mounts are also disclosed.

Abstract: A method for generating amplified terahertz radiation includes inducing a first volume of a gas to produce a seed plasma and emit pulsed seed terahertz radiation by focusing an optical seed beam in the first volume. The seed terahertz radiation is then amplified by focusing an optical gain beam to produce a gain plasma in a second volume overlapping with the pulsed seed terahertz radiation remote from the seed plasma. The method may be implemented in a system for detecting and analyzing a remotely-located object such as an explosive material, a biological agent, and a chemical agent.

Abstract: A method of analyzing a remotely-located object includes the step of illuminating at least a portion of a targeted object with electromagnetic radiation to induce a phase transformation in the targeted object, wherein the phase transformation produces an emitter plasma, which emits terahertz radiation. The method also includes the step of ionizing a volume of an ambient gas to produce a sensor plasma by focusing an optical probe beam in the volume and the step of detecting an optical component of resultant radiation produced from an interaction of the focused optical probe beam and the terahertz radiation in the sensor plasma. Detecting an optical component of the resultant radiation emitted by the sensor plasma facilitates detection of a characteristic fingerprint of the targeted object imposed onto the terahertz radiation produced as a result of the induced phase transformation.

Abstract: A method for generating terahertz radiation includes inducing a background plasma in a volume of a gas by focusing a first optical beam in the volume, and generating pulsed terahertz radiation with enhanced generation efficiency by focusing a second time-delayed optical beam in the background plasma. The method may be implemented in a system for detecting and analyzing a remotely-located object.

Abstract: A method and system for imaging an object includes transmitting distinguishable electromagnetic waves from a plurality of radiators of an antenna array, wherein each of the distinguishable electromagnetic waves is distinguishable from others by a detector. Each of the radiators transmits radiation comprising a different distinguishable electromagnetic wave. The method also includes imaging at least a portion of the antenna array onto a targeted object, wherein each image area of a plurality of image areas on the targeted object corresponds to an image of a respective radiator of the antenna array, and detecting a plurality of resultant electromagnetic waves, wherein the resultant electromagnetic waves are transmitted, scattered, or reflected by respective image areas on the targeted object in response to each of the respective image areas being illuminated by the radiation transmitted by the respective radiator of the source array.

Abstract: A method of analyzing a remotely-located object includes the steps of inducing a volume of an ionized ambient gas to emit pulsed terahertz radiation directed toward a targeted object by focusing an optical pump beam in the volume and ionizing another volume of the ambient gas to produce a sensor plasma by focusing an optical probe beam in the other volume of ambient gas. The interaction, in the sensor plasma, of the focused optical probe beam and an incident terahertz wave, which is produced by the targeted object reflecting, scattering, or transmitting the pulsed terahertz radiation, produces a resultant radiation. Detecting an optical component of the resultant radiation emitted by the sensor plasma facilitates detection of a signature of the targeted object imposed onto the incident terahertz radiation.