Abstract: A high-voltage switch, whose operation leverages the speed of electrons to generate the “on” time of the pulse in combination with the speed of light to generate the “off” time of the pulse, is described. In one example, the high-voltage switch includes a first electrode, a second electrode spaced apart from the first electrode, a region of non-absorbing material occupying a portion of the space between the first and second electrodes and allowing a laser pulse to propagate therethrough without substantial absorption, and a region of absorbing material occupying another portion of the space and producing a charged particle cloud upon receiving the laser pulse. The high-voltage switch remains “on” upon the charged particle cloud reaching an electrode and until it has been collected by the electrode, and where the high-voltage switch remains “off” subsequent to the collection and until another generated charged particle cloud reaches the electrode.

Abstract: Apparatuses comprising cascaded or series configurations of Mach-Zehnder electrooptic modulators, where the nonlinearities of the cascaded and series configurations of Mach-Zehnder electrooptic modulators increase signal bandwidth and boost signal fidelity in electronic digital to analog converters. The Mach-Zehnder electrooptic modulators are combined with photodiode detectors that are used to convert signals from the optical domain to the electrical domain.

Abstract: Space-to-time pulse shaping techniques are provided that maintain high fidelity with a practical output coupler, maintain an output resolution that is no longer than the input pulse, and are scalable to long records while maintaining fine resolution.

Abstract: The nonlinearities of cascaded and series configurations of Mach-Zehnder electrooptic modulators are utilized to increase signal bandwidth and boost signal fidelity in electronic digital to analog converters.

Abstract: A method for increasing the MeV hot electron yield and secondary radiation produced by short-pulse laser-target interactions with an appropriately high or low atomic number (Z) target. Secondary radiation, such as MeV x-rays, gamma-rays, protons, ions, neutrons, positrons and electromagnetic radiation in the microwave to sub-mm region, can be used, e.g., for the flash radiography of dense objects.

Abstract: A high-voltage switch, whose operation leverages the speed of electrons to generate the “on” time of the pulse in combination with the speed of light to generate the “off” time of the pulse, is described. In one example, the high-voltage switch includes a first electrode, a second electrode spaced apart from the first electrode, a region of non-absorbing material occupying a portion of the space between the first and second electrodes and allowing a laser pulse to propagate therethrough without substantial absorption, and a region of absorbing material occupying another portion of the space and producing a charged particle cloud upon receiving the laser pulse. The high-voltage switch remains “on” upon the charged particle cloud reaching an electrode and until it has been collected by the electrode, and where the high-voltage switch remains “off” subsequent to the collection and until another generated charged particle cloud reaches the electrode.

Abstract: Space-to-time pulse shaping techniques are provided that maintain high fidelity with a practical output coupler, maintain an output resolution that is no longer than the input pulse, and are scalable to long records while maintaining fine resolution.

Abstract: The present invention extends the resolution capability for shaping optical pulses on laser systems from the current state of the art resolution of ˜250 ps to ˜1 ps by utilizing a hybrid of EOM and spectral shaping technologies. In one embodiment, a short pulse derived from a mode-locked laser oscillator is dispersed using a dispersive stretcher to about 250 ps, providing a linear mapping of spectrum to time. A typical spectral shaper is used to directly write the desired temporal pattern in the spectral domain to produce a crudely patterned waveform that may also suffer from chirp. The chirp is removed by a process known as difference frequency generation by mixing it with a pulse derived from an equally chirped frequency-doubled pump in an optical parametric amplifier. The pattern is then focused in time, which is accomplished in one embodiment by propagating the pattern through a dispersive element.

Abstract: The present invention extends the resolution capability for shaping optical pulses on laser systems from the current state of the art resolution of ˜250 ps to ˜1 ps by utilizing a hybrid of EOM and spectral shaping technologies. In one embodiment, a short pulse derived from a mode-locked laser oscillator is dispersed using a dispersive stretcher to about 250 ps, providing a linear mapping of spectrum to time. A typical spectral shaper is used to directly write the desired temporal pattern in the spectral domain to produce a crudely patterned waveform that may also suffer from chirp. The chirp is removed by a process known as difference frequency generation by mixing it with a pulse derived from an equally chirped frequency-doubled pump in an optical parametric amplifier. The pattern is then focused in time, which is accomplished in one embodiment by propagating the pattern through a dispersive element.

Abstract: A method for increasing the MeV hot electron yield and secondary radiation produced by short-pulse laser-target interactions with an appropriately high or low atomic number (Z) target. Secondary radiation, such as MeV x-rays, gamma-rays, protons, ions, neutrons, positrons and electromagnetic radiation in the microwave to sub-mm region, can be used, e.g., for the flash radiography of dense objects.

Abstract: Single-shot transient optical signals are recorded in a time regime of picoseconds to nanosecond. An auxiliary pump beam is crossed through the signal to sample a diagonal ‘slice’ of space-time, analogous to a rolling shutter. The slice is then imaged onto an ordinary camera, where the recorded spatial trace is a direct representation of the time content of the signal. The pump samples the signal by optically exciting carriers that modify the refractive index in a conventional semiconductor wafer. Through use of birefringent retarders surrounding the wafer, the integrating response of the rapidly excited but persistent carriers is differentiated by probing with two polarization-encoded time-staggered signal replicas that are recombined to interfere destructively.

Abstract: A system for aerially surveying an area where a plane may have crashed in water and locating pings from the plane's black box using a laser on an aerial platform that produces laser pulses; using a launch telescope to direct the laser pulses to the water producing scattering from the laser pulses and a continuous stream of backscatter; using a receiving telescope to collect the continuous stream of backscatter; using an interferometer operatively connected to the receiving telescope to produce two outputs, wherein one output is the continuous stream of backscatter, and wherein the other output is a delayed replica of the first output; and using a data collection and analysis unit operatively connected to the interferometer to produce a measurement of the sound.

Abstract: Single-shot transient optical signals are recorded in a time regime of picoseconds to nanosecond. An auxiliary pump beam is crossed through the signal to sample a diagonal ‘slice’ of space-time, analogous to a rolling shutter. The slice is then imaged onto an ordinary camera, where the recorded spatial trace is a direct representation of the time content of the signal. The pump samples the signal by optically exciting carriers that modify the refractive index in a conventional semiconductor wafer. Through use of birefringent retarders surrounding the wafer, the integrating response of the rapidly excited but persistent carriers is differentiated by probing with two polarization-encoded time-staggered signal replicas that are recombined to interfere destructively.

Abstract: A system for aerially surveying an area where a plane may have crashed in water and locating pings from the plane's black box using a laser on an aerial platform that produces laser pulses; using a launch telescope to direct the laser pulses to the water producing scattering from the laser pulses and a continuous stream of backscatter; using a receiving telescope to collect the continuous stream of backscatter; using an interferometer operatively connected to the receiving telescope to produce two outputs, wherein one output is the continuous stream of backscatter, and wherein the other output is a delayed replica of the first output; and using a data collection and analysis unit operatively connected to the interferometer to produce a measurement of the sound.

Abstract: Cladding-pumped Raman fiber lasers and amplifiers provide high-efficiency conversion efficiency at high brightness enhancement. Differential loss is applied to both single-pass configurations appropriate for pulsed amplification and laser oscillator configurations applied to high average power cw source generation.

Abstract: Spatial mode conversion modules are described, with the capability of efficiently transforming a given optical beam profile, at one plane in space into another well-defined optical beam profile at a different plane in space, whose detailed spatial features and symmetry properties can, in general, differ significantly. The modules are comprised of passive, high-efficiency, low-loss diffractive optical elements, combined with Fourier transform optics. Design rules are described that employ phase retrieval techniques and associated algorithms to determine the necessary profiles of the diffractive optical components. System augmentations are described that utilize real-time adaptive optical techniques for enhanced performance as well as power scaling.

Abstract: Spatial mode conversion modules are described, with the capability of efficiently transforming a given optical beam profile, at one plane in space into another well-defined optical beam profile at a different plane in space, whose detailed spatial features and symmetry properties can, in general, differ significantly. The modules are comprised of passive, high-efficiency, low-loss diffractive optical elements, combined with Fourier transform optics. Design rules are described that employ phase retrieval techniques and associated algorithms to determine the necessary profiles of the diffractive optical components. System augmentations are described that utilize real-time adaptive optical techniques for enhanced performance as well as power scaling.

Abstract: An optical source capable of enhanced scaling of pulse energy and brightness utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.

Abstract: Spatial mode conversion modules are described, with the capability of efficiently transforming a given optical beam profile, at one plane in space into another well-defined optical beam profile at a different plane in space, whose detailed spatial features and symmetry properties can, in general, differ significantly. The modules are comprised of passive, high-efficiency, low-loss diffractive optical elements, combined with Fourier transform optics. Design rules are described that employ phase retrieval techniques and associated algorithms to determine the necessary profiles of the diffractive optical components. System augmentations are described that utilize real-time adaptive optical techniques for enhanced performance as well as power scaling.

Abstract: Spatial mode conversion modules are described, with the capability of efficiently transforming a given optical beam profile, at one plane in space into another well-defined optical beam profile at a different plane in space, whose detailed spatial features and symmetry properties can, in general, differ significantly. The modules are comprised of passive, high-efficiency, low-loss diffractive optical elements, combined with Fourier transform optics. Design rules are described that employ phase retrieval techniques and associated algorithms to determine the necessary profiles of the diffractive optical components. System augmentations are described that utilize real-time adaptive optical techniques for enhanced performance as well as power scaling.