40 results about "Pulse distortion" patented technology

An amplified laser source for amplifying a laser projection that includes a diode laser source modulated by a pulse generator applying an alternate high and low voltages higher and lower than a threshold voltage for projecting a modulated optical signal. The laser source further includes a first erbium-doped fiber (EDF) for amplifying the modulated optical signal. The laser source further includes a set of Bragg gratings for receiving the modulated optical signal from the first EDF for reflecting a grating-specific pulse-distortion-reduced optical signal. The laser source further includes an electro-absorption (EA) modulator synchronized with the pulse generator for increasing an extinction ratio of the optical signals. The laser source further includes a second erbium doped fiber (EDF) for receiving and amplifying the optical signal from the EA modulator wherein the second erbium doped fiber (EDF) having a length of several meters and a diameter greater than or equal to thirty-five micrometers.

The invention describes a number of differential, balanced high-speed circuits that permit the design of a receiver with Electronic Dispersion Compensation (EDC) on a single semiconductor substrate, including the functions of an analog Fast Forward Equalizer (FFE), a Clock and Data Recovery, a Decision Feedback Equalizer (DFE), enhanced by additional circuits that permit control of the slicing level to compensate for pulse distortion, and control of the phase offset to set the optimal eye sampling time when a distorted signal is received. To provide the utmost speed of operation, all circuits including the phase locked loop, operate as differential circuits which include a number of improvements in the design of the charge pump, the decision feedback equalizer, the slicing level control, and others.

An all-fiber chirped pulse amplification (CPA) system and method is provided that utilizes a hollow core photonic bandgap fiber as a pulse compressor and a dispersion compensating optical fiber as a pulse stretcher that are matched with respect to both the amount and slope of dispersion to avoid peak power-limiting pulse distortion. The CPA system includes a rare earth ion-doped optical fiber amplifier having an input and an output that amplifies optical pulses having a center wavelength of λc, a pulse compressing length L1 of hollow core photonic bandgap fiber having a dispersion value D1 and a dispersion slope S1 that varies over a wavelength λ of the pulses that is optically connected to the output of the fiber amplifier and having a k-parameter defined by a ratio of D1 over the slope of the function D1(λ) that is larger than about 50, and a pulse stretching length L2 of dispersion compensating optical fiber connected to the input of the fiber amplifier having a dispersion value D2 and dispersion slope S2. The lengths are selected such that L1D1=−L2D2, and the center wavelength λc of the inputted optical pulses is preferably close to the center wavelength of the bandgap of the photonic bandgap fiber.

Methods and instruments for suppression of multiple scattering noise and extraction of nonlinear scattering components with measurement or imaging of a region of an object with elastic waves, where at least two elastic wave pulse complexes are transmitted towards said region where said pulse complexes are composed of a high frequency (HF) and a low frequency (LF) pulse with the same or overlapping beam directions and where the HF pulse is so close to the LF pulse that it observes the modification of the object by the LF pulse at least for a part of the image depth. The frequency and / or amplitude and / or phase of said LF pulse relative to said HF pulse varies for each transmitted pulse complex in order to nonlinearly manipulate the object elasticity observed by the HF pulse along at least parts of its propagation, and where received HF signals are picked up by transducers from one or both of scattered and transmitted components of the transmitted HF pulses. Said received HF signals are processed to form measurement or image signals for display, and where in the process of forming said measurement or image signals said received HF signals are one or both of delay corrected with correction delay in the fast time (depth-time), and pulse distortion corrected in the fast time, and combined in slow time to form noise suppressed HF signals or nonlinear scattering HF signals that are used for further processing to form measurement or image signals. The methods are applicable to elastic waves where the material elasticity is nonlinear in relation to the material deformation.

A gate driving apparatus and image display device using the same and driving method thereof comprises a start pulse generator which generates a second gate start pulse by a logic operation of a first gate start pulse and a gate output enable signal, a shift register which generates a shift signal by sequentially shifting the second gate start pulse in accordance with a gate shift clock, and an output unit which outputs the shift signal in accordance with the gate output enable signal.

Circuitry used to de-skew data channels coupling parallel data signals over a communication link employs SOI circuitry that is subject to generating pulse distortion due to the history effect modifying threshold voltages. To substantially eliminate the pulse distortion, data signals are XOR with a repeating scramble data pattern that generates scrambled data with a minimum average ratio of logic ones to logic zeros logic zeros to logic ones. The scrambled data is sent over the communication link and de-skewed in the SOI circuitry with little or no pulse distortion. The scramble data pattern is again generated at the receiver side of the communication link after a delay time to synchronize the logic states of the scramble data pattern that generated the scrambled data with the scrambled data at the receiver side. The delayed scrambled data pattern is again XOR'ed with the scrambled data to recover the data signal.

A shift register and a method for driving the same are disclosed. The shift register includes a plurality of stages serially connected to each other. Each of the stages independently generates first and second scan pulses. The first scan pulse is simultaneously applied to a previous stage and to a corresponding gate line of a liquid crystal panel. The second scan pulse is applied to a next stage. The shift register prevents scan pulses applied to each stage from being distorted, and prevents a multi-output signal from being generated.

The specification describes an optical transmission system for high speed, high capacity digital pulse transmission, i.e. at least 10 Gb / s at a duty cycle of at least 10%, which uses transmission fiber with a dispersion value greater than 20 ps / (nm-km) or more negative than -5 ps / (nm-km). The system operates in the pseudo-linear transmission mode (PLTM). In the PLTM it was discovered that pulse distortion decreases, i.e. eye closure penalty actually decreases, as the dispersion value increases. System performance actually improves by increasing the value of absolute dispersion of the transmission fiber.

The invention provides an optical transmitter comprising a differential encoder having first and second outputs, the first and second outputs being of opposite polarity to one another, a first RZ converter connected to the first output of the differential encoder and a second RZ converter connected to the second output of the differential encoder, and a dual electrode Mach Zehnder modulator to which an unmodulated coherent light source is coupled, wherein the output of the first RZ converter is connected to a first electrode of the Mach Zehnder modulator and the output of the second RZ converter is connected to a second electrode of the Mach Zehnder modulator. The invention provides improved signal integrity as compared with existing RZ-DPSK solution through the use of high quality RZ drivers. Furthermore, the invention gives rise to controllable RZ pulse edge chirping, providing rapid pulse compression or broadening through a dispersive fibre length. This can be used to mitigate pulse distortion in non-linear transmission links.

The invention provides a digital-analogue converter, a drive device of a display and an image data conversion method. The digital-analogue converter comprises a gray-scale decision circuit and a pulse segmenting unit, wherein the gray-scale decision circuit outputs a decision signal to the pulse segmenting unit according to a numerical value of image data; and the pulse segmenting unit connects the gray-scale decision circuit for receiving a judgment signal, selects reference signals with different numerical value orders according to the judgment signal and compares the reference signals withthe image data to generate different numbers of sub-work cycles and avoid a frame flicker and pulse distortion loss.

The invention provides a distortion signal generating device for video signal analyzer calibration. The distortion signal generating device comprises a line-by-line phase inversion distortion generating device including a differential phase error programming device and a phase error programming device with non-linear chromaticity distortion, a superposed continuous wave distortion generating device including a luminance and noise level signal generating device and an AM / PM noise signal generating device, a superposed pulse distortion generating device including a 2T sinusoidal square wave distortion signal generating device and a short-time waveform distortion signal generating device, a distortion generating device with signal component amplitude changing, and a distortion generating device for signal component splitting, wherein the distortion generating device with signal component amplitude changing includes a luminance non-linear distortion signal generating device and a differential gain distortion signal generating device and the distortion generating device for signal component splitting includes an SINX / X frequency distortion signal generating device and a chrominance / luminance gain difference signal generating device.

A method and apparatus for writing data to an optical storage medium are disclosed. A write signal indicating power levels of a laser diode is generated by encoding and decoding codewords. The codewords are generated and decoded according to a Successive State Change Criterion (SSCC) or SSCC II proposed by the present invention. By doing so, toggling (i.e. state changing) times occurring in channels transferring the codewords can be significantly reduced to avoid the problems of pulse distortion and disappearance in high frequency transmission. Alternatively, toggles appearing in the respective channels can be spread to avoid interference between the channels. Further, a phase adjustment device for adjusting a phase of each codeword is disclosed.

The invention provides a digital-analogue converter, a drive device of a display and an image data conversion method. The digital-analogue converter comprises a gray-scale decision circuit and a pulse segmenting unit, wherein the gray-scale decision circuit outputs a decision signal to the pulse segmenting unit according to a numerical value of image data; and the pulse segmenting unit connects the gray-scale decision circuit for receiving a judgment signal, selects reference signals with different numerical value orders according to the judgment signal and compares the reference signals with the image data to generate different numbers of sub-work cycles and avoid a frame flicker and pulse distortion loss.

A method and apparatus for writing data to an optical storage medium are disclosed. A write signal indicating power levels of a laser diode is generated by encoding and decoding codewords. The codewords are generated and decoded according to a specific requirement proposed by the present invention. By doing so, toggling (i.e. state changing) times occurring in channels transferring the codewords can be significantly reduced to avoid the problems of pulse distortion and disappearance in high frequency transmission. Alternatively, toggles appearing in the respective channels can be spread to avoid interference between the channels. Further, a phase adjustment device for adjusting a phase of each codeword is disclosed.

The invention discloses a radar pulse signal distortion measurement method, relates to the technical field of radar signal reconnaissance, can quantitatively evaluate and evaluate signal distortion degree, obtain specific pulse distortion parameter values, and can greatly improve algorithm development efficiency. The method includes the following steps: carrying out short-time Fourier transform on the signal to be tested, and extracting a graph of the maximum power of the signal changing with time from the result of the short-time Fourier transform. Calculate the normalized cross-correlation parameter, the normalized change trend parameter and the normalized pulse splitting parameter of the signal to be tested based on the graph of the maximum signal power versus time. The pulse distortion parameter is obtained by weighting and summing the normalized cross-correlation parameter, the normalized change trend parameter, the normalized pulse splitting parameter and the noise-to-signal ratio of the signal to be measured.