摘要:
Terahertz quantum cascade (QC) devices are disclosed that can operate, e.g., in a range of about 1 THz to about 10 THz. In some embodiments, QC lasers are disclosed in which an optical element (e.g., a lens) is coupled to an output facet of the laser's active region to enhance coupling of the lasing radiation from the active region to an external environment. In other embodiments, terahertz amplifier and tunable terahertz QC lasers are disclosed.
摘要:
A brassiere is provided having a pair of breast-receiving cups, each cup comprising at least one fabric layer molded to at least one foam layer, and an inner breast-receiving side and a lower periphery and an upper periphery. A first shaped pocket is formed on the breast-receiving side having a slit formed therein. A first shaped cushion conforming substantially to the shape of the pocket is removably insertable into the pocket to provide breast enhancement to a wearer.
摘要:
A data processing system and method for processing images received from multiple cameras are provided. The system includes a memory for receiving first and second images associated with respective cameras; a determiner adapted to process the first and the second images to identify respective objects depicted therein; the determiner is further adapted to calculate a predetermined metric associated with projections of the respective objects in a first frame of reference; and a labeler adapted to assign a common label to the objects according to the predetermined metric.
摘要:
The present invention provides quantum cascade lasers and amplifier that operate in a frequency range of about 1 Terahertz to about 10 Terahertz. In one aspect, a quantum cascade laser of the invention includes a semiconductor heterostructure that provides a plurality of lasing modules connected in series. Each lasing module includes a plurality of quantum well structure that collectively generate at least an upper lasing state, a lower lasing state, and a relaxation state such that the upper and the lower lasing states are separated by an energy corresponding to an optical frequency in a range of about 1 to about 10 Terahertz. The lower lasing state is selectively depopulated via resonant LO-phonon scattering of electrons into the relaxation state.
摘要:
An optical correlator for correlating incident optical signals is described. The correlator comprises a transmission line in close juxtaposition to a photoconductor. The photoconductor may be positioned within the transmission line. The transmission line and the photoconductor may be monolithically integrated on a substrate. The optical correlator has an electrical non-linear response to the incident optical signals that results from a voltage divider formed from the combination of the transmission line and the photoconductor. The electrical non-linear response is proportional to a second-order intensity autocorrelation function g.sup.(2) (.tau.). The response time of the electrical nonlinear response is less than the width of the narrowest pulse of the optical signals and may be less than twenty picoseconds.
摘要:
A catalyst component for olefin polymerization comprising an α-cyanosuccinate compound as an internal electron donor, a catalyst comprising the catalyst component, and use of the catalyst in olefin polymerization. When used in propylene polymerization, the catalyst can exhibit good catalytic activity and good hydrogen response, and the resulting polymer can have a good isotacticity and a good molecular weight distribution.
摘要:
The present invention provides frequency tunable solid-state radiation-generating devices, such as lasers and amplifiers, whose active medium has a size in at least one transverse dimension (e.g., its width) that is much smaller than the wavelength of radiation generated and/or amplified within the active medium. In such devices, a fraction of radiation travels as an evanescent propagating mode outside the active medium. It has been discovered that in such devices the radiation frequency can be tuned by the interaction of a tuning mechanism with the propagating evanescent mode.
摘要:
A DC/DC converter, a power converter and a control method thereof are disclosed, wherein the DC/DC converter includes an output circuit, a rectangular wave generator, a resonant tank, a detection unit and a control unit. The output circuit has a load. The rectangular wave generator converts an input voltage into driving pulses. The resonant tank provides a first voltage based on the driving pulses for the output circuit. The detection unit detects a signal related to a state of the load. When the state of the load is a light-load or a no-load, the control unit controls the rectangular wave generator in a hiccup mode to reduce a ratio of a work period to a stop period, or makes that number of the driving pulses within the current work period is less than the number of the driving pulses when a duty ratio is 50%.
摘要:
Terahertz quantum cascade (QC) devices are disclosed that can operate, e.g., in a range of about 1 THz to about 10 THz. In some embodiments, QC lasers are disclosed in which an optical element (e.g., a lens) is coupled to an output facet of the laser's active region to enhance coupling of the lasing radiation from the active region to an external environment. In other embodiments, terahertz amplifier and tunable terahertz QC lasers are disclosed.
摘要:
A DC/DC converter, a power converter and a control method thereof are disclosed, wherein the DC/DC converter includes an output circuit, a rectangular wave generator, a resonant tank, a detection unit and a control unit. The output circuit has a load. The rectangular wave generator converts an input voltage into driving pulses. The resonant tank provides a first voltage based on the driving pulses for the output circuit. The detection unit detects a signal related to a state of the load. When the state of the load is a light-load or a no-load, the control unit controls the rectangular wave generator in a hiccup mode to reduce a ratio of a work period to a stop period, or makes that number of the driving pulses within the current work period is less than the number of the driving pulses when a duty ratio is 50%.