摘要:
Disclosed herein are methods of detecting organic materials, and more particularly, methods of detecting organic materials using terahertz spectroscopy. The method of detecting organic material using terahertz spectroscopy includes suspending organic material in a medium to form a sample; irradiating the sample with an illumination beam of electromagnetic radiation, the illumination beam having a plurality of frequencies in the range of about 100 GHz to about 2 THz; detecting radiation transmitted through and/or reflected from the sample; and, analyzing the detected radiation to identify the organic material, wherein the medium is selected from the group consisting of agar, guar gum, gellan gum, carrageenan, xantham gum, fibrous sodium pectate, and other agar substitutes.
摘要:
An apparatus for analyzing, identifying or imaging a target including an integrated dual laser module coupled to a pair of photoconductive switches to produce CW signals in the range of frequencies from 100 GHz to over 2 THz focused on and transmitted through or reflected from the target; and a detector for acquiring spectral information from signals received from the target and using a multi-spectral homodyne process to generate an electrical signal representative of some characteristics of the target with resolution less than 250 MHz. The photoconductive switches are activated by laser beams from the dual laser module. The lasers in the module are tuned to different frequencies and have two distinct low frequency identification tones respectively that are used in conjunction with a stable optical filter element to permit precise determination of the offset frequency of the lasers.
摘要:
An apparatus for analyzing, identifying or imaging an target including first and second laser beams coupled to a pair of photoconductive switches to produce CW signals in one or more bands in a range of frequencies greater than 100 GHz focused on and transmitted through or reflected from the target; and a detector for acquiring spectral information from signals received from the target and using a multi-spectral heterodyne process to generate an electrical signal representative of some characteristics of the target. The lasers are tuned to different frequencies and a frequency shifter in the path of one laser beam allows the terahertz beam to be finely adjusted in one or more selected frequency bands.
摘要:
Disclosed herein is a method of detecting a contaminant material in a food sample. The method includes irradiating a food sample with a beam of electromagnetic radiation, the beam having a plurality of frequencies in the range of about 100 GHz to about 2 THz; detecting radiation transmitted and/or reflected from the food sample; and, analyzing the detected radiation to determine the presence of contaminant material. The contaminant material may be melamine, cyanuric acid, ammeline, or ammelide.
摘要:
An apparatus for analyzing, identifying or imaging an target including first and second laser beams coupled to a pair of photoconductive switches to produce CW signals in one or more bands in a range of frequencies greater than 100 GHz focused on and transmitted through or reflected from the target; and a detector for acquiring spectral information from signals received from the target and using a multi-spectral heterodyne process to generate an electrical signal representative of some characteristics of the target. The lasers are tuned to different frequencies and a frequency shifter in the path of one laser beam allows the terahertz beam to be finely adjusted in one or more selected frequency bands.
摘要:
Disclosed herein are methods of detecting organic materials, and more particularly, methods of detecting organic materials using terahertz spectroscopy. The method of detecting organic material using terahertz spectroscopy includes suspending organic material in a medium to form a sample; irradiating the sample with an illumination beam of electromagnetic radiation, the illumination beam having a plurality of frequencies in the range of about 100 GHz to about 2 THz; detecting radiation transmitted through and/or reflected from the sample; and, analyzing the detected radiation to identify the organic material, wherein the medium is selected from the group consisting of agar, guar gum, gellan gum, carrageenan, xantham gum, fibrous sodium pectate, and other agar substitutes.
摘要:
An apparatus for analyzing, identifying or imaging an target including an integrated dual laser module coupled to a pair of photoconductive switches to produce cw signals in the range of frequencies from 100 GHz to over 2 THz focused on and transmitted through or reflected from the target; and a detector for acquiring spectral information from signals received from the target and using a multi-spectral homodyne process to generate an electrical signal representative of some characteristics of the target with resolution less than 250 MHz. The photoconductive switches are activated by laser beams from the dual laser module. The lasers in the module are tuned to different frequencies and a phase shifter in the path of one beam allows the beams to have an adjustable phase difference.
摘要:
A fiber optic gyroscope including an optical circulator in the path of said first and second beams for providing polarized first and second beams of identical polarization. A phase modulator couples the first and second beams to the first and second end respectively of the fiber loop, and couples for receiving the return first and second beams from the second and first ends respectively of the fiber loop. First and second photodiodes are coupled to the optical circulator for receiving the optical signal from the first and second return beams.
摘要:
Attaching an attachment surface of an electrically conductive workpiece to an electrically conductive support surface is described. In one aspect, a biasing force is distributed at least partially around a weld region of the workpiece to urge the attachment surface of the workpiece against the support surface in a way which at least resists welding induced movement of the workpiece relative to the support arrangement. An electrode arrangement, having an electrode tip, contacts the workpiece to provide for substantially compliant movement of the electrode tip against the weld region in directions that are parallel to the support surface. In another aspect, a combined manipulation/welding arrangement is supported for controlled movement with a free end configured for engaging the workpiece to bias the workpiece against the support surface to manipulate the workpiece against the surface and to conduct an electrical current, while holding the workpiece, for welding to the support surface.
摘要:
An apparatus for analyzing, identifying or imaging an target including first and second laser beams coupled to a pair of photoconductive switches to produce CW signals in one or more bands in a range of frequencies greater than 100 GHz focused on, and transmitted through or reflected from the target; and a detector for acquiring spectral information from signals received from the target and using a multi-spectral heterodyne process to generate an electrical signal representative of some characteristics of the target. The lasers are tuned to different frequencies and a phase modulator in the path of one laser beam allows the constructive or destructive interference of the signals on the detector as the laser beams are swept in frequency to be adjusted to achieve greater resolution in one or more selected frequency bands.