77results about How to "Improve modulation" patented technology

A novel polarization maintaining optical fiber, which can be used as a high-power polarization maintaining fiber laser or amplifier, is described. Insensitivity of the polarization state to external fiber bending and temperature changes is accomplished by minimizing polarization mode-coupling via reducing stresses inside the fiber core via increasing the fiber diameter. Alternatively, polarization mode-coupling can be minimized by an optimization of the fiber coating to minimize stresses at the interface between the fiber and the coating. As a result insensitivity to polarization mode-coupling is obtained at greatly reduced values of birefringence compared to small-diameter fibers. The fiber is of significant use in any application where polarization stability is important, and will be useful in telecommunications applications in particular for reducing polarization mode dispersion. An implementation in a parabolic pulse-producing fiber laser is also described as one specific high power example.

Wireless communication apparatus (20) includes a transmitter (22), which includes a first plurality of transmit antennas (26) mutually separated by a first spacing, and which is configured to transmit signals via the transmit antennas over multiple spatial sub-channels, the signals having respective phases. A receiver (24), which includes a second plurality of receive antennas (28) mutually separated by a second spacing, is configured to receive the signals over the multiple spatial sub-channels via the receive antennas. The first and second spacings are chosen so as to maximize a linear independence of the respective phases of the signals received at the receive antennas.

A data transmission apparatus and method using a full-diversity, full-rate STBC are provided. In the data transmission apparatus, a serial-to-parallel converter converts an input bit stream to parallel binary vectors. A bit/symbol mapper generates modulator input symbols by combining the bits of the binary vectors. A modulator modulates the modulator input symbols to complex symbols. A transmit matrix block encoder encodes the complex symbols using a transmit matrix and transmits the coded symbols through corresponding transmit antennas.

A technique to allow enhanced stations and legacy stations to work with each other without the inefficiencies of signaling overhead in the prior art is disclosed. An enhanced station transmits an initial, short frame using a modulation compatible with legacy stations. The frame sets the duration for a frame exchange—consisting of a data frame, followed by acknowledgement frame—in which the data frame is transmitted using an enhanced modulation format. The duration specified in the transmitted initial frame covers the time interval of the subsequent frame exchange. All stations, including legacy stations, listen in on the frame exchange and refrain subsequently from transmitting spontaneously for the time interval covered by the duration. Alternatively, the frame exchange can comprise multiple data frames with corresponding acknowledgement frames. The enhanced station can also transmit, during the remaining frame exchange, one or more intermediate frames that indicate duration.

The present invention provides for the development of endocytosis-sensitive probes, and a remote method for measuring cellular endocytosis. These probes are based on the reduced water permeability of a nanoparticle or liposomal delivery system, and inherent degradability or disruption of barrier integrity upon endocytosis. The invention also provides for liposomes having combined therapeutic and diagnostic utilities by co-encapsulating ionically coupled diagnostic and therapeutic agents, in one embodiment, by a method using anionic chelators to prepare electrochemical gradients for loading of amphipathic therapeutic bases into liposomes already encapsulating an imaging agent. The invention provides for imaging of therapeutic liposomes by inserting a lipopolymer anchored, remotely sensing reporter molecules into liposomal lipid layer. The invention allows for an integrated delivery system capable of imaging molecular fingerprints in diseased tissues, treatment, and treatment monitoring.

A method for repairing a defect in cartilage, comprising the provision of apertures in the cartilage by drilling holes at the base of the cartilage defect, which holes may enter the mesenchymal depot, introducing a porous scaffold material containing a plurality of magnetic particles into the apertures, and subsequently and sequentially injecting magnetically-tagged cartilage growth promoting materials such as various growth factors or chondrocytes into the area of the defect. The magnetically tagged growth promoting material is then drawn into the apertures by magnetic attraction of the magnetic particles contained in the porous scaffold material, either by virtue of the particles being permanently magnetic, or by the imposition of an external magnetic field. The present application claims the biodegradable porous scaffold material containing the plurality of magnetic particles.

A method and apparatus for two-dimensional gas chromatography (GC), including a valve having first and second positions (P1, and P2), and first through fourth sample flow paths (FP1-FP4). In P1, a first gas sample is collected from a first dimension GC column via FP1, a first pressure source and a first, second dimension GC column are connected via FP2, a second pressure source and a second, second dimension GC column are connected via FP3, and FP4 is disconnected. In P2, the first sample in FP1 is introduced to the second, second dimension GC column via FP1, with aid of the second pressure source, a second gas sample is collected from the first dimension GC column via FP2, the first pressure source and the first, second dimension GC column via FP4 are connected, and FP3 is disconnected.

An implantable graft device having treated yarn is disclosed. The device comprises a graft body forming a lumen defining a longitudinal axis and comprising proximal and distal ends. The graft body comprises a woven fabric having warp yarns aligned in a first direction and a weft yarns aligned in a second direction. At least one of the weft yarns and the warp yarns has an agent applied thereto defining treated yarns of the graft body.

A manufacturing method is described for a wind turbine blade, where layers of fibre material are laid up in a mould to form a portion of the blade structure. The fibre layers are infused with a resin which is subsequently cured to form the hardened blade structure. Some of the layers of fibre material are arranged so that a portion of the layers are kept resin-free during the infusion and curing steps, so that the fibre layer extends freely out from the external surface of the blade, preferably at the blade trailing edge, to provide a flexible blade trailing edge to reduce blade operational noise.

Radio-frequency (RF) excitation is used for direct detection of hybridization events at microelectrodes with surface-attached DNA oligomers. A homodyne reflectometer operates on a high frequency carrier to detect the presence of a low-frequency modulation signal. Without non-linearities in an interface, the modulation signal is not impressed upon the carrier signal. As such, the reflectometer can sensitively measure changes in dielectric properties without interference from other sources of capacitance/resistance unrelated to the reaction at the surface.

A spatial terahertz wave phase modulator based on the high electron mobility transistor is provided. The phase modulator combines the quick-response high electron mobility transistor with a novel metamaterial resonant structure, so as to rapidly modulate terahertz wave phases in a free space. The phase modulator includes a semiconductor substrate, an HEMT epitaxial layer, a periodical metamaterial resonant structure and a muff-coupling circuit. A concentration of 2-dimensional electron gas in the HEMT epitaxial layer is controlled through loading voltage signals, so as to change an electromagnetic resonation mode of the metamaterial resonant structure, thereby achieving phase modulation of terahertz waves. The phase modulator has a phase modulation depth of over 90 degrees within a large bandwidth, and a maximum phase modulation depth is about 140 degrees. Furthermore, the phase modulator is simple in structure, easy to machine, high in modulation speed, convenient to use, and easy to package.

An optical lens assembly for image taking, sequentially from an object side to an image side along an optical axis comprises: the first lens element with refractive power, a bi-convex second lens element with positive refractive power, the third lens element with negative refractive power having a concave object-side surface and a convex image-side surface, the fourth lens element with positive refractive power having a convex object-side surface and a concave image-side surface. All four lenses may be made of plastic with bi-aspherical surfaces. Additionally, the optical lens assembly for image taking satisfies conditions to shorten the total length and reduce the sensitivity in order to achieve the goal of a fine aberration correction and ready for its use in cameras and camera mobile phones.

Stabilization of an injection locked optical frequency comb is achieved through polarization spectroscopy of an active laser cavity, eliminating optical PM sidebands inherent in previous stabilization methods. Optical SNR of 35 dB is achieved. A monolithic AlInGaAs quantum well Fabry-Prot laser injection locked to a passively mode-locked monolithic laser is presented here. The FP laser cavity can be used as a true linear interferometric intensity modulator for pulsed light.

A brake assembly for a hydraulic brake system of a handlebar-steered vehicle, the brake assembly including a housing mountable to a handlebar of the vehicle and having a chamber formed therein. The brake assembly is provided with a variable rate linkage. A piston assembly is received and axially guided within the chamber and is provided with a piston adjustment mechanism that does not affect the function of the variable rate linkage.

The present disclosure describes semiconductor external cavity laser with wide bandwidth frequency modulation capabilities. The laser is preferably packaged in a standard form-factor package, such as a 14-pin butterfly package. The front end of the cavity comprises an integrated planar circuit (e.g., silica-on-silicon planar lightwave circuit with Bragg gratings), and the “back facet” of the laser is implemented as a high-reflection (HR) coated LiNbO₃ phase tuning section in the double pass configuration. AC-voltage signal applied to the electrodes of phase tuning section modulates a refractive index of the propagating TE-polarization mode of external cavity and produces frequency modulation. Such frequency modulation is not associated with any thermal behavior of the gain element included in the external cavity laser, and has a negligible phase delay over a wide bandwidth.

In an exposure apparatus of the invention, for a spatial light modulator, each of a plurality of pixel portions fewer than the total number of the pixel portions is controlled with a control signal generated according to exposure information. Namely, a part of the pixel portions is controlled without controlling a whole of the pixel portions on the substrate. Thus, the number of pixels in the pixel portions is decreased, and transfer time of the control signal becomes short. This enables modulation speed of the laser beam to be increased and the high-speed exposure to be performed. An incorporated laser light source, in which the laser beams are incorporated and struck on the optical fiber, is preferable to the laser device. By adopting the incorporated laser light source, high brightness and high output can be obtained, and it is preferable to the exposure of the spatial light modulator. Since the fiber array is obtained with few optical fibers, it is low cost. Since the number of optical fibers is few, the light-emitting region is further decreased when the optical fibers are arrayed.

A method of driving a probe of a scanning probe microscope. The intensities of first and second radiation beams are modulated; and the beams are directed simultaneously onto the probe whereby each beam heats the probe and causes the probe to deform, typically by the photothermal effect. The optical system is arranged to direct the centres of the beams onto different locations on the probe. This enables the location of each beam to be chosen to optimise its effect. A lens receives the first and second beams and focuses them onto the probe. A beam combiner is arranged to receive and combine the beams and direct the combined beams towards the probe.