Abstract: A laser architecture for selectively producing short high-energy laser pulses having octave-spanning, continuous tunability. Two oppositely chirped pulses are used in combination with a pair of tunable pulse stretcher/compressors to produce a short, high-energy, tunable, broadband pulse.

Abstract: A laser architecture for selectively producing short high-energy laser pulses having octave-spanning, continuous tunability. Two oppositely chirped pulses are used in combination with a pair of tunable pulse stretcher/compressors to produce a short, high-energy, tunable, broadband pulse.

Abstract: A laser architecture for selectively producing short high-energy laser pulses having octave-spanning, continuous tunability. Two oppositely chirped pulses are used in combination with a pair of tunable pulse stretcher/compressors to produce a short, high-energy, tunable, broadband pulse.

Abstract: A plurality of gas jet nozzles having equal angular separation around a central axis eject gas flows towards the central axis. The gas flows collide and form a gas channel from the neutral gas, the gas channel having a gas density depression at the center of the intersecting gas flow, where the gas density depression is surrounded by a higher density gaseous wall along the central axis. Ionization of the gas in the center produces a plasma channel that can guide a laser pulse fired into the gas along the central axis. The geometric arrangement of the gas jets and/or the backing pressure of the gas flows are configured to produce a gas channel having a predetermined density profile such that the ionized gas forms a plasma channel laser guiding structure configured to guide a laser pulse having predetermined spatial parameters.

Abstract: A plurality of gas jet nozzles having equal angular separation around a central axis eject gas flows towards the central axis. The gas flows collide and form a gas channel from the neutral gas, the gas channel having a gas density depression at the center of the intersecting gas flow, where the gas density depression is surrounded by a higher density gaseous wall along the central axis. Ionization of the gas in the center produces a plasma channel that can guide a laser pulse fired into the gas along the central axis. The geometric arrangement of the gas jets and/or the backing pressure of the gas flows are configured to produce a gas channel having a predetermined density profile such that the ionized gas forms a plasma channel laser guiding structure configured to guide a laser pulse having predetermined spatial parameters.

Abstract: A method for generating coherent, polarized, and tunable X-rays using a single laser pulse is provided. An ultrashort laser pulse is fired into a plasma. As the laser beam travels through the plasma, some of its photons are backscattered, e.g., through Raman backscattering, to generate a counter-propagating photon beam that is co-linear with the original laser beam. When the backscattered photons interact with high-energy accelerated periodic electron bunches, coherent X-rays are generated through Compton backscattering of the photons off of the electrons. The energy of the backscattered X-rays can be tuned by tuning one or more characteristics of the laser pulse and/or the plasma.

Abstract: Methods for producing a laser-guided underwater electrical discharge are provided. One or more electrodes defining a desired electrical discharge path are situated in a body of water and are attached to an external electrical power supply. A high-powered, intense laser beam is fired through one or more focusing lenses into the water. The laser beam forms an optical filament in the water, which in turn forms an ionized channel having a much greater conductivity than the surrounding water. An external power supply drives an electrical discharge along the path of the ionized channel due to its greater conductivity.

Abstract: A high power ultrashort chirped pulse amplifier laser system, with a chirped pulse amplifier laser module including an optical pulse stretcher, at least one optical power amplifier, and an optical pulse compressor, and a beam interferometer module in the optical path. The beam interferometer receives splits the pulse into at least two pulses, adds a time delay to at least one of the pulses and recombines the pulses to produce a temporally modulated pulse. The resulting modulated output pulse from the CPA laser module can have enhanced laser contrast due to greatly reduced subpicosecond pedestal in the immediate region of the peak pulse, or can have other desirable characteristics.

Abstract: A method for generating coherent, polarized, and tunable X-rays using a single laser pulse is provided. An ultrashort laser pulse is fired into a plasma. As the laser beam travels through the plasma, some of its photons are backscattered, e.g., through Raman backscattering, to generate a counter-propagating photon beam that is co-linear with the original laser beam. When the backscattered photons interact with high-energy accelerated periodic electron bunches, coherent X-rays are generated through Compton backscattering of the photons off of the electrons. The energy of the backscattered X-rays can be tuned by tuning one or more characteristics of the laser pulse and/or the plasma.

Abstract: A method for generating an extended underwater plasma. A first laser pulse is fired into a body of water to form an underwater optical filament coinciding with a low-energy plasma. A second laser pulse is fired into the water, targeted at the plasma. The second pulse heats the plasma, causing the formation of an extended superheated plasma volume in the water. The two laser pulses can be simultaneous or can be sequential, with the second pulse following the first pulse by up to the filament plasma lifetime. The extended superheated plasma creates an underwater acoustic pulse, wherein the duration, waveform and directivity of the pulse can be tailored by controlling the shape of the underwater laser-generated plasma.

Abstract: A high power ultrashort chirped pulse amplifier laser system, with a chirped pulse amplifier laser module including an optical pulse stretcher, at least one optical power amplifier, and an optical pulse compressor, and a beam interferometer module in the optical path. The beam interferometer receives splits the pulse into at least two pulses, adds a time delay to at least one of the pulses and recombines the pulses to produce a temporally modulated pulse. The resulting modulated output pulse from the CPA laser module can have enhanced laser contrast due to greatly reduced subpicosecond pedestal in the immediate region of the peak pulse, or can have other desirable characteristics.

Abstract: Methods for producing a laser-guided underwater electrical discharge are provided. One or more electrodes defining a desired electrical discharge path are situated in a body of water and are attached to an external electrical power supply. A high-powered, intense laser beam is fired through one or more focusing lenses into the water. The laser beam forms an optical filament in the water, which in turn forms an ionized channel having a much greater conductivity than the surrounding water. An external power supply drives an electrical discharge along the path of the ionized channel due to its greater conductivity.

Abstract: A method for generating an extended underwater plasma. A first laser pulse is fired into a body of water to form an underwater optical filament coinciding with a low-energy plasma. A second laser pulse is fired into the water, targeted at the plasma. The second pulse heats the plasma, causing the formation of an extended superheated plasma volume in the water. The two laser pulses can be simultaneous or can be sequential, with the second pulse following the first pulse by up to the filament plasma lifetime. The extended superheated plasma creates an underwater acoustic pulse, wherein the duration, waveform and directivity of the pulse can be tailored by controlling the shape of the underwater laser-generated plasma.