3424 results about "Gain" patented technology

High dynamic range brightness information is acquired by inputting detection current to a high (adjustable) gain resettable integrator whose output V(t) is compared to a Vth threshold by a comparator whose output is counted by a reset counter as V(t).gtoreq.Vth. When a desired count is attained, data acquisition ends, the counter is read, and the entire circuit is reset. A TOF data acquisition circuit includes first and second sequences of series-coupled delay units, and a like number of latch units coupled between respective delay units. A phase discriminator compares output from each chain and feedback a signal to one of the chains and to a comparator and can equalize delay through each chain. A control voltage is coupled to the remaining chain to affect through-propagation delay time. The latch units can capture the precise time when V(t).gtoreq.Vth. Successive measurement approximation can enhance TOF resolution.

A desired pattern may be cut into a stent preform by impinging a laser beam onto the stent preform. The laser beam is formed using a laser system comprising a resonator cavity for resonating laser radiation, a gain medium contained in the resonator cavity, a pump for periodically pumping the gain medium and an electro-optical modulator in communication with the resonator cavity. The laser system produces a radiation pulse for each pump period. Each radiation pulse is conditioned by suppressing at least a portion of the pulse. The pulse may also be modulated with an electro-optical modulator to produce a pulse train of ordered pulses of radiation. Each pulse train is output from the optical cavity as an output laser beam which is directed at the stent preform to cut a desired pattern in the stent preform.

An optical article having a rare earth doped, fluorinated aluminosilicate glass core composition consisting essentially, in mole %, of: - SiO2 0-90 - GeO2 0-90 - Na2O 0-25 - Li2O 0-10 - K2O 0-25 - Rb2O 0-25 - Cs2O 0-25 - Al2O3 5-40 - Ga2O3 5-40 - RE2(1)O3 0-40 - RE2(2)O3 0-1 - Er2O3 0.001-5 - Yb2O3 0-5 - PbO 0-15 - RO 0-20 - ZnO 0-10 - ZrO2 0-2 - TiO2 0-2 - Nb2O5 0-10 - Ta2O5 0-10 - P2O5 0-5 - B2O3 0-15 - As2O3 0-10 - Sb2O3 0-20 - Na2Cl2 0-10 - Bi2O3 0-5, and - up to 15 weight % fluorine in the form of at least one of a fluorinated component of the glass composition and a batch constituent selected from a group consisting of at least one of AlF3, REF3, NH5F2, NaF, Na2SiF6, Na3AlF6, where RE(1) is at least one of Y, La, Gd, and Lu; RE(2) is at least one of Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, and Tm; R is at least one of Ba, Ca, Mg, and Sr; (SiO2+GeO2) is in the range (40-90); and (Al2O3+Ga2O3)>(RO+"alk"2O+RE2O3) where "alk" is at least one of Li, Na, K, Cs, and Rb. A cullet-in-tube method for making continuous clad filament is also described. The invention provides for an optical waveguiding article having relatively high gain, a relatively flat gain spectrum, compatibility with conventional silica fiber, good durability and ease of manufacture.

A laser system capable of efficient production of high energy sub-nanosecond pulses in the 2-15 μm spectral region is disclosed. Diode pumped solid state lasers are used as pump sources. The system design is simple, reliable and compact allowing for easy integration. The laser system includes a combination of compact solid-state ˜1 micron laser sources, producing high power picosecond pulses, with optical parametric amplification and a quasi-continuous wave laser for seeding the amplification process that enables the efficient conversion of the high power ˜1 micron laser radiation to tuneable mid-infrared sub-ns pulses. New parametric processes are presented for achieving high gains in bulk nonlinear crystals. Furthermore, a method of exceeding the fundamental conversion efficiency limit of direct three wave mixing is presented. The compact and robust nature of this novel laser system opens up the use of high power and high peak power mid-infrared laser pulses to a wide variety of important medical and dental applications.

A tunable optical filter is provided that includes an array of independently tunable filter elements. Each of the elements is located along a different optical path that extends between an input and an output port. Optical assemblies for receiving an incident optical signal for providing a filtered optical signal are also provided. In one embodiment, polarization independent spectral filtering can be achieved. Wavelength selectable add/drop multiplexers and demultiplexers, dynamic gain equalizers and attenuators, optical channel blockers and branch filters, switches, and modulators are also provided. Furthermore, methods for constructing and operating filters consistent with this invention are also provided.

The invention provides a measuring device and method for the target line-of-sight angel offset and distance. The device is composed of a four-quadrant avalanche photodetector, a receiving and sending optical unit, a noise compensation circuit, a four-circuit front amplification circuit, a video amplification circuit, an automatic gain amplification circuit, a peak keeping circuit, an AD conversion circuit, a laser, a dominant wave sampling circuit, a summing circuit, a time identifying circuit, a time test circuit and a digital processing circuit, wherein the receiving and sending optical unit enables narrow pulse laser rays emitted by the laser to be converged on the photoelectric detector to form echo light spots after target reflection, photovoltaic conversion of the four-quadrant avalanche photodetector, front amplification, video amplification and automatic gain amplification are conducted, narrow-pulse peak keeping is conducted, transmission of the AD conversion circuit is conducted, and the digital processing circuit extracts the digital line-of-sight angel offset; summing is conducted on the four-circuit front amplification circuit, the dominant wave sampling circuit is combined, the time identifying circuit determines laser emitting and echo coming and returning time, the time is transmitted to the time identifying circuit to be measured, and the digital processing circuit decodes the corresponding distance.

The invention relates to a sensing method with an optical-fiber Bragg grating laser device. An optical-fiber Bragg grating is used as a reflector of the resonant cavity, an active optical fiber capable of generating sufficient gains is added, and a double wavelength/multiple wavelength optical-fiber Bragg grating laser device is formed under the action of a pump light source and used as a sensor. When the outside strain, temperature and other physical quantities act on the sensing system, the beat signal frequency among the double wavelength or multiple wavelength laser can shift, and counter stress, temperature and other physical parameters can be measured precisely by detecting the beat signal frequency information. The invention has the advantages of simple manufacture, stable and reliable operation, stable measurement result and high precision, and is free from the interference of light intensity, polarization and other optical information quantities. The multipoint distribution sensing measurement can be realized in a frequency-division multiplexing mode. An electrooptical modulator is added before the spectrum analyzer starts detection so as to randomly adjust the beat signal frequency, thereby greatly reducing the spectral range of the spectrum analyzer and reducing the detection cost.

A phase-based TOF system preferably generates an optical waveform with fast rise and fall times, to enhance modulation contrast, notwithstanding there will be many high order harmonics. The system is preferably operated with an odd number of phases, to reduce system bias error due to the higher order harmonics, while maintaining good modulation contrast, without unduly increasing system memory requirements. Preferably the system can dynamically calibrate (and compensate for) higher order harmonics in the TOF generated optical energy waveform, over time and temperature. Within the optical energy transmission channel, or within the optical energy detection channel, detection amplifier gain may be modified, and/or detector signal integration time may be varied, and/or digital values may be employed to implement calibration and error reduction The resultant TOF system can operate with improved phase-vs-distance characteristics, with reduced calibration requirements.

Blood cells of interest are readily distinguishable from other blood cells and look-a-like particles found in a blood sample by their back-scatter signature. A preferred method for differentiating platelets in a blood sample is to irradiate the cells and particles, one at a time, with a beam of radiation, and to detect back-scattered (reflected) radiation using a plurality of optical fibers to transmit the back-scattered radiation to a high-gain photodetector, e.g. a photomultiplier tube. Preferably, the back-scatter signal so obtained is combined with a second signal representing, for example, either the level of forward-scatter within a prescribed, relatively narrow angular range, or the level of side-scattered radiation, or the level of attenuation of the cell-irradiating beam caused by the presence of the irradiated cell or particle in the beam, or the electrical impedance of the irradiated cell or particle, to differentiate the cells of interest. The method and apparatus of the invention are particularly useful in differentiating platelets and basophils in a blood sample.

Examples of systems and methods to provide estimates of dark current for pixels of a photosensor as a function of the temperature of the sensor and the gain applied to the photosensor are described. In various implementations, the dark current estimated for each pixel can depend at least partly on a global scale factor and a global bias that depend on temperature and gain and a temperature-independent and gain-independent offset value for each pixel. The scale, bias, and offsets may be determined from multiple dark field images taken by the sensor over a range of operating temperatures. In some cases, the scale and bias can be determined using a subset of less than all the image pixels. Scale and bias derived for a particular sensor can be used in the calibration of different sensors.

A backlight device for a display comprising (1) a side-lit light source, (2) a light guide plate and (3) a turning film comprising a light entry and a light exit surface comprising lenticular elements on the exit surface and prismatic structures on the entry surface, wherein the average values of the parameters of the features and the thickness of the film are selected to provide a peak output angle of ±10° from normal to the light exit surface of the light guide plate and an optical gain of at least 1.25. Also disclosed are methods of making the turning film and a display incorporating the backlight.

A beam-forming apparatus and method for improving system performance using a spatial interpolation and at least one Angle of Arrival (AoA) in a system based on regular spatial sampling is provided. The AoA is estimated using a carrier-to-interference ratio. Beam-forming angles are distributed and steered in a predefined scheme such that an identical process is applied in all directions. According to this steering, a linear system model is computed based on regular spatial sampling using regular spatial separation at beam angles. Beam-forming performance is improved by compensating for a difference between adaptive and sector-type arrays. Only the steps of computing a spatial interpolation and determining an angle range for beam-forming using at least one AoA are added. The precision of estimating an AoA and the precision of beam-forming increase without an additional antenna. Because the system is simpler than that of an adaptive beam-forming system, significant gain is obtained.

The invention provides a method for defect detection and surface measurement of a silicon wafer. According to the method, the phase-measuring deflectometry(PMD) is used for surface measurement of a silicon wafer. The PMD-based mirror object three-dimensional surface measurement method is a highly-sensitive, high-precision, quick and incoherent optical full-field measurement technology, and an experimental device is simple and mainly comprises a computer, a digital camera and a display screen. When the PMD is used for surface measurement of the silicon wafer, the surface gradient distribution of the silicon wafer can be directly obtained, the surface curvature distribution of the silicon wafer can be obtained so long as gradient derivation is performed, defects are detected through curvature distribution, the surface height data of the silicon wafer can be obtained through gradient integration, and accordingly, the three-dimensional shape can be observed. The invention has the main gain that the high-precision and quick full-field measurement technology is provided to realize surface defect detection and surface measurement of the silicon wafer.

The invention discloses a tapered photonic crystal quantum cascade laser for outputting near-diffraction-limited beams and the manufacture method thereof. The laser comprises a substrate, as well as a lower waveguide layer, an active area, an upper waveguide layer, an upper cover layer, an upper contact layer, an ohmic contact layer, an electrical insulation layer, a front side electrode and a rear side electrode on the substrate. The laser has the ridge-shaped mesa double-grooved waveguide structure, wherein the ridge-shaped mesa structure includes a main control oscillation area with a uniform ridge width and a gain amplification area with a tapered structure. The photonic crystal structure is used for providing a distributed feedback waveguide manufactured between the upper contact layer and the ohmic contact layer. The tapered photonic crystal quantum cascade laser can acquire singe-mode near-diffraction-limited beam output. The waveguide structure with the combination of the ridge-shaped mesa and the tapered gain amplification area can greatly reduce the far-field divergence angle, thereby improving the output power while obviating the heat dissipation problem that is difficult to avoid for the similar wide-ridge large-power devices.

A laser diode capable of being easily mounted, and a laser diode device in which the laser diode is mounted are provided. A hole is disposed in a semiconductor layer, and a p-type electrode and an n-type semiconductor layer are electrically connected to each other by a bottom portion (a connecting portion) of the hole. Thereby, the p-type electrode has the same potential as the n-type semiconductor layer, and a saturable absorption region is formed in a region corresponding to a current path. Light generated in a gain region (not shown) is abosorbed in the saturable absorption region to be converted into a current. The current is discharged to a ground via the p-side electrode and the bottom portion, and an interaction between the saturable absorption region and the gain region is intitiated, thereby self-oscillation can be produced.