165 results about "Pulse shaper" patented technology

A waveform adaptive transmitter that conditions and/or modulates the phase, frequency, bandwidth, amplitude and/or attenuation of ultra-wideband (UWB) pulses. The transmitter confines or band-limits UWB signals within spectral limits for use in communication, positioning, and/or radar applications. One embodiment comprises a low-level UWB source (e.g., an impulse generator or time-gated oscillator (fixed or voltage-controlled)), a waveform adapter (e.g., digital or analog filter, pulse shaper, and/or voltage variable attenuator), a power amplifier, and an antenna to radiate a band-limited and/or modulated UWB or wideband signals. In a special case where the oscillator has zero frequency and outputs a DC bias, a low-level impulse generator impulse-excites a bandpass filter to produce an UWB signal having an adjustable center frequency and desired bandwidth based on a characteristic of the filter. In another embodiment, a low-level impulse signal is approximated by a time-gated continuous-wave oscillator to produce an extremely wide bandwidth pulse with deterministic center frequency and bandwidth characteristics. The UWB signal may be modulated to carry multi-megabit per second digital data, or may be used in object detection or for ranging applications. Activation of the power amplifier may be time-gated in cadence with the UWB source thereby to reduce inter-pulse power consumption. The UWB transmitter is capable of extremely high pulse repetition frequencies (PRFs) and data rates in the hundreds of megabits per second or more, frequency agility on a pulse-to-pulse basis allowing frequency hopping if desired, and extensibility from below HF to millimeter wave frequencies.

A system and method are described for optoacoustic imaging a structural or compositional characteristic of an biological object using a coherent, broad range frequency tunable, electromagnetic radiation source and a pulse shaper to generate a sequence of electromagnetic radiation excitation signals.

A control system and apparatus for use with an ultra-fast laser is provided. In another aspect of the present invention, the apparatus includes a laser, pulse shaper, detection device and control system. A multiphoton intrapulse interference method is used to characterize the spectral phase of laser pulses and to compensate for any distortions in an additional aspect of the present invention. In another aspect of the present invention, a system employs multiphoton intrapulse interference phase scan. Furthermore, another aspect of the present invention locates a pulse shaper and/or MIIPS unit between a spectral dispersion point in a laser oscillator and an output of a laser amplifier.

A control system and apparatus for use with an ultra-fast laser is provided. In another aspect of the present invention, the apparatus includes a laser, pulse shaper, detection device and control system. A multiphoton intrapulse interference method is used to characterize the spectral phase of laser pulses and to compensate any distortions in an additional aspect of the present invention. In another aspect of the present invention, a system employs multiphoton intrapulse interference phase scan. Furthermore, another aspect of the present invention locates a pulse shaper and/or MIIPS unit between a laser oscillator and an output of a laser amplifier.

A laser system is provided which selectively excites Raman active vibrations in molecules. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and remote sensing.

A high performance radio frequency receiver includes a low noise amplifier with large binary and stepped gain control range, controlled impedance, and enhanced blocker immunity, for amplifying and converting a radio frequency signal to a current; a pulse generator for generating in-phase and quadrature pulses; a crossover correction circuit and pulse shaper for controlling a crossover threshold of the pulses and interaction between in-phase and quadrature mixers; and a double balanced mixer for combining the RF signal with the pulses to generate an intermediate frequency or baseband zero intermediate frequency current-mode signal. The in-phase and quadrature pulses have a duty cycle of 20-35%. The intermediate frequency signal and second order harmonics may be filtered with a high frequency low pass filter and a current injected complex direct-coupled filter. Decreased die size, current drain, cost, and complexity, as well as improvements in gain, 1/f noise, noise figure, sensitivity, and linearity may result.

A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and a spectrometer. Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal. In yet another aspect of the present invention, a multiphoton intrapulse interference phase scan system and method characterize the spectral phase of femtosecond laser pulses. Fiber optic communication systems, photodynamic therapy and pulse characterization tests use the laser system with additional aspects of the present invention.

An optical beam synthesizer formed on a single chip is provided. It allows M-PSK modulation for both beam polarizations. The synthesizer comprises an optical pulse shaper and two M-PSK modulators for each polarization. A single-chip-integrated analyzer is provided to receive a modulated data. Analyzer comprises a pulse shaper operating as an optical sampler and a pair of 90-degrees optical hybrids for each polarization. Each optical hybrids mix incoming portions of the modulated beams with portions of the local oscillator beams. Both the synthesizer and the analyzer include a set of mirrors located on the back and front surfaces of the chips to create compact designs. The output beams from the analyzer are detected by a set of balanced photodiodes, and the data is recovered. It is another object of the invention to provide a communication system for data transmission having the synthesizer and the analyzer.

A system for measuring the height of bin content includes a transmitter for transmitting an acoustic pulse towards the upper surface of the content, a non-collinear receiver array for receiving an echo of the pulse and producing signals in response to the echo, and a processing apparatus for computing one or more directions of arrival of the signals from the upper surface to the array along with corresponding measured distances. Preferably, the receivers are transducers that also serve as transmitters. Two or more such measured distances constitute a map of the upper surface for estimating the quantity of the bin content. Preferably, the system includes a pulse shaper and repeater for optimizing the pulse shape relative to the signals.

A method for overcoming the drawback in a fiber CPA laser system that includes a process of generating a large negative TOD by implementing an AODS in a pulse shaper as a dispersive component. The AODS is implemented to arbitrarily modulate both the spectrum shape and phase to control with controllable amplitude to generate different orders of dispersions including a large negative TOD for compensating the positive TOD generated by the pulse stretching and amplification processes. The AODS, implemented as a dispersive component, can be an active and controllable dispersive component to generate adjustable levels of dispersions for flexibly compensating any order of dispersions generated in the amplifier chain including the nonlinear phase shift. The AODS implemented as a dispersive component can be an active and programmable dispersive component to interactively generate adjustable levels of dispersions in response to output laser amplitude and pulse shape measurements for flexibly compensating any order of dispersions generated in the amplifier chain including the nonlinear phase shift to achieve the shortest pulse duration.

The invention relates to a method for improving the machining efficiency of micro-channel preparation through femtosecond laser, which belongs to the technical field of femtosecond laser application. The method includes the steps: firstly, generating the femtosecond pulse laser by the aid of a femtosecond laser system, adjusting energy by means of combination of a half wave plate and a polarizing film and modulating the femtosecond laser into femtosecond interval pulse sequence by the aid of a pulse shaper; secondly, reflecting the pulse sequence laser obtained in the first step to an objective lens for focusing through a reflector, realizing imaging by the aid of a CCD (charge coupled device) and a lighting source, moving a six-dimensional precision electric control platform and positioning a laser focus on the lower surface of a sample horizontally placed on the six-dimensional precision electric control platform; and thirdly, controlling the six-dimensional precision electric control platform to move along a laser propagation direction by the aid of a computer to machine a micro-channel on the sample. As the femtosecond laser is modulated into the femtosecond interval pulse sequence by the aid of the pulse shaper, the micro-channel preparation efficiency is improved. Moreover, introduction of a vibration source is omitted, so that controllability of precision machining cannot be reduced.

The invention relates to an optical diagnostic system on the basis of laser spontaneous Raman scattered ray imaging, belonging to the technical field of laser spectrum testing. According to the invention, a laser pulse shaper is arranged between a laser and a gas sample tank; a cutoff device is arranged at one end of a laser emergence quartz window of the gas sample tank; a total reflective mirror is arranged between an outlet of a scattered ray output quartz window of the gas sample tank and a line light source collector at an angle of 45 degrees; an optical filter is arranged between the line light source collector and an inlet of a spectrometer; an outlet of the spectrometer is respectively connected with an ICCD (Intensified Charge Coupled Device) and an inlet of a measurement and control machine; the ICCD is also respectively connected with the laser and the measurement and control machine; and due to the adoption of the optical diagnostic system, the phenomena of gas fracturing,damage to optical elements and the quartz windows, ignition of inflammable gases and the like can be effectively avoided, the weak Raman scattering signal to noise ratio can be effectively improved, and a multichannel gas Raman spectrum experiment proves that the optical diagnostic system can be applied to synchronous quantitative measurement in a plurality of regions of the gas mixture concentration in an optical engine.