Abstract: An ultrasonic transmitting/receiving circuit equipped with: a semiconductor circuit element which comprises at least three terminals including a first terminal connected to a plurality of transducer elements that constitute an ultrasonic probe, a second terminal connected to a transmission signal generating circuit, and a third terminal serving as an output terminal of an amplifier of a reception signal from the transducer element, and which has a function of amplifying a signal inputted from one terminal by the other terminal and outputting the amplified signal between at least two terminals among the above-said three terminals; and a control unit which performs control so as to cause the semiconductor circuit element to perform a first function of functioning as a switch for inputting a transmission signal to the transducer element and a second function of amplifying the reception signal received from the transducer element.

Abstract: There is provided a seismic imaging technology for imaging a subsurface structure by processing measured data reflected from the subsurface structure after a wave from a source wave has been propagated to the subsurface structure. According to an aspect, there is provided a seismic imaging method for obtaining imaging data of a subsurface structure through waveform inversion using a macro-velocity model as an initial value, wherein the macro-velocity model which is used as the initial value for the waveform inversion is calculated by: calculating a velocity difference function which is a difference between a real velocity and an initial velocity model, wherein the velocity difference function is a ratio of measured seismic scattered energy and modeled scattered energy based on the initial velocity model; and calculating the macro-velocity model by updating the initial velocity model with the velocity difference function.

Abstract: An ultrasound probing device including: a box; a locating mechanism to provide a position of the box in relation to a reference frame associated with an object to be examined; a mechanism to determine a delay law based on focusing parameters, representing a desired position of a focal point in relation to a reference frame associated with the box; a controller to provide control signals based on the delay law; transducers attached to the box, to receive control signals and, in response, to transmit ultrasonic waves in the object respectively delayed according to the delay law to focus at the focal point defined by the focusing parameters; and a mechanism updating the focusing parameters based on predefined associations between positions on a desired path of the box in relation to the reference frame associated with the object and corresponding focusing parameter values and the position of the box.

Abstract: A laser diode assembly includes a mode-locked laser diode device, where a light output spectrum shows long-wavelength shift by self-phase modulation, an external resonator, and a wavelength selective element. A long wavelength component of a pulsed laser beam emitted through the external resonator from the mode-locked laser diode device is extracted by the wavelength selective element, and output to the outside.

Abstract: An optical semiconductor device includes: semiconductor lasers; a wave coupling section multiplexing light output by the semiconductor lasers; an optical amplifying section amplifying output light of the wave coupling section; first optical waveguides respectively optically connecting respective semiconductor lasers to the wave coupling section; a light intensity lowering section located in each of the first optical waveguides and lower light intensity of reflected light that is reflected at a reflecting point located in the optical semiconductor device and that returns to the respective semiconductor lasers; to decrease line width of the light output by the semiconductor lasers.

Abstract: Complex-valued sensitivity data structures corresponding to respective candidate survey settings are provided, where the sensitivity data structures relate measurement data associated with a target structure to at least one parameter of a model of the target structure. Based on the sensitivity data structures, a subset of the candidate survey settings is selected according to a criterion for enhancing resolution in characterizing the target structure.

Abstract: In a method for functional testing of an ultrasonic sensor on a motor vehicle, the ultrasonic sensor is controlled in such a way that it emits an ultrasonic signal having a frequency of a secondary mode of the ultrasonic sensor, the ultrasonic signal is reflected by a surface in the region around the vehicle, and at least one transmission path or one transmitting unit of the ultrasonic sensor is classified as functional if the reflected signal is received by the ultrasonic sensor itself or by another ultrasonic sensor on the motor vehicle.

Abstract: Presented are systems and methods for deploying wireless data acquisition modules that facilitate autonomous initialization. The wireless data acquisition modules may initiate a initialization process in response to a stimulus associated with being deployed. The wireless data acquisition module may further conduct a neighbor discovery process and in turn establish a data transfer path among one or more other wireless data acquisition modules. Further, information obtained during a series of autonomous tests may be communicated during the neighbor discovery process and the establishment of the data transfer path may at least in part be based on the information obtained in the autonomous tests.

Abstract: A method and apparatus for providing a high peak power optical beam. The method includes interleaving pulse trains of different wavelengths and spatially and temporally overlapping the different wavelengths to produce an amplified output beam with very high peak power.

Abstract: Systems and methods for modulating the output of a difference frequency generator such as an OPO, OPA or OPG include a pump fiber laser having at least one internal, directly modulatible component, wherein the pump fiber laser produces a pump signal, and a difference frequency generator coupled to the pump fiber laser. The difference frequency generator is configured for accepting the pump signal of the pump fiber laser and producing an output signal, wherein parameters of the output signal are determined based on direct modulation of the internal, directly modulatible component of the pump fiber laser.

Abstract: An optical source having a fiber emitting controlled single-transverse mode radiation at a wavelength of less than 1030 nm, includes at least one laser diode suitable for emitting a pumping wave; and a section of sheathed amplifying optical fiber having two ends, the amplifying optical fiber comprising a core and a pumping sheath, the fiber being doped with a rare earth dopant; a device for coupling the pumping source in the sheath of the doped fiber, characterized in that the core of the doped fiber includes a cylindrical portion doped with a rare earth element selected among ytterbium, neodymium, and thulium, in order to obtain a refractive index of the core that is higher than the refractive index of the sheath; the excitation wavelength of the laser diode is between 750 nm and 960 nm; the diameter of the sheath is greater than 50 microns, and the surface ratio of the doped core to the pumping sheath is between 8 and 50.

Abstract: A method and a system of acquiring and processing multi-source broadband marine seismic data in such a way that at least a part of said acquired data is partially or fully de-ghosted on the receiver side and then partially or fully re-assembled to a pre-stack dataset. At least one non-uniformly horizontal streamer is towed and at least two seismic sources emit seismic signals at spaced apart positions. Further presented is a method of processing marine seismic data by using the thus resulting notch diversity in these two (or more) seismic records to de-ghost the dataset, gathering two or more recorded seismic signals having substantially the same source-sensor offset and substantially the same common mid-point at different sensor depths, the sensor depths at least different enough to enable identification of seismic signals originating from ghosting. The gather is de-ghosted, thus obtaining seismic data with significantly broader bandwidth.

Abstract: An optical device comprising a first optical coupler located over a surface of a substrate such that the optical coupler is able to end-couple to an optical core of a first optical fiber having an end facing and adjacent to the first optical coupler and the surface. The optical device further comprises a second optical coupler located over the surface such that the second optical coupler is able to end-couple to an optical core having an end facing and adjacent to the second optical coupler. The optical device also comprises a pump coupler being configured to couple pump light to an optical path that connects the first optical coupler and the second optical coupler.

Abstract: A rare earth doped optical fiber amplifier is configured to have an enlarged core region and a trench formed adjacent to the core, where at least an inner portion of the trench is also formed to include a rare earth dopant. The presence of the rare earth dopant in the inner region of the cladding minimizes transient power fluctuations within the amplifier as the number of optical signals being amplified changes. The addition of rare earth dopant to the cladding increases the overlap between the pump, signal and the rare earth ions and thus improves the gain efficiency for the optical signal. The relatively large core diameter increases the saturation power level of the rare earth dopant and decreases the transients present in the gain as the input signal power fluctuates.

Abstract: A semiconductor optical element includes an optical waveguide formed on a semiconductor substrate, which includes: a single mode guide portion which guides input light in a single mode; a curved portion disposed at a downstream side of the single mode guide portion in a waveguide direction of the light and guiding the light in a single mode; and a flared portion disposed at a downstream side of the curved portion in the waveguide direction and of which waveguide width is widened toward the waveguide direction, so that the flared portion can guide the light in a single mode at an light-input side and the flared portion can guide the light in a multi-mode at a light-output side. The input light is optically-amplified by each of the active layers in the single mode guide portion, the curved portion and the flared portion by an optically-amplifying effect of the active layers.

Abstract: For disposing projections of insulating film protruding into a hollow part in CMUT in order to suppress injection of electrical charge into the insulating film due to contact of a lower surface of a membrane with a lower surface of the hollow part, there are provided a structure of disposed projections preferred for suppressing increase in driving voltage for CMUT and decrease in receiving sensitivity, and an ultrasonic diagnostic apparatus using the same.

Abstract: A device and related fabrication method is provided for an organic/inorganic hybrid optical amplifier with a function of converting infrared light to visible light. The hybrid device integrates an inorganic heterojunction phototransistor (HPT), an embedded metal electrode mirror with a dual function as an optical mirror and charge injection electrode, and an organic light emitting diode (OLED). This integrated optical amplifier is capable of amplifying the incoming light and producing light emission with a power greater than that of the incoming signal. In the second aspect of the invention, the optical amplifier is capable of detecting an incoming infrared electromagnetic wave and converting the wave back to a visible light wave. The optical device has dual functions of optical power amplification and photon energy up-conversion. The optical amplifier device consists of an InGaAs/InP based HPT structure as photodetector, gold-coated metals as embedded mirror and a top-emission OLED.

Abstract: The semiconductor optical amplifier device includes a plurality of active units. Each active unit includes an active stripe structure of an optical amplifying medium and a current circuit configured to inject current into the corresponding active stripe structure. Each active stripe structure extends from an input end to an output end. An optical splitter device is configured to split an incoming signal light and for distributing corresponding parts of the incoming signal light into the different input ends of the active stripe structures. The optical splitter device is configured to supply each active stripe structure with the same signals.

Abstract: For the purpose of reducing the cost and power consumption of an optical amplification system provided with an optical amplifier, an excitation light distribution device of the present invention comprises an excitation light source output unit which outputs excitation light, an optical branching unit with variable branching ratio which branches and outputs the excitation light, and a control unit which, on the basis of information on an optical signal to be amplified by the excitation light outputted by the optical branching unit, controls at least either the branching ratio of the optical branching unit or the optical output power of the excitation light source output unit.

Abstract: An inventive composite optical gain medium capable includes a thin-disk gain layer bonded to an index-matched cap. The gain medium's surface is shaped like a paraboloid frustum or other truncated surface of revolution. The gain medium may be cryogenically cooled and optically pumped to provide optical gain for a pulsed laser beam. Photons emitted spontaneously in the gain layer reflect off or refract through the curved surface and out of the gain medium, reducing amplified spontaneous emission (ASE). This reduces limits on stored energy and gain imposed by ASE, enabling higher average powers (e.g., 100-10,000 Watts). Operating at cryogenic temperatures reduces thermal distortion caused by thermo-mechanical surface deformations and thermo-optic index variations in the gain medium. This facilitates the use of the gain medium in an image-relayed, multi-pass architecture for smoothed extraction and further increases in peak pulse energy (e.g., to 1-100 Joules).