Abstract: An assembly for providing a concentrated, vertically stacked array of laser beams from a horizontally offset array of electrically serially-connected metallic microchannel heat sinks each bearing a laser diode bar. The heat sinks are mounted on horizontally offset planes of the manifold which has coolant channels serving adjacent heat sinks that are separated from each to increase the electrical resistance of the fluid path between adjacent ones of said heat sinks. Stepped optical deflectors re-arrange the horizontally emitted laser beams into vertical stack.

Abstract: A diode end-pumped solid state laser is provided which produces improved power output, long term stability and improved conversion efficiency from the pumping power, high as well as low power operation while maintaining certain desirable common characteristics such as TEM00 operation, circular outputs, readily aligned systems and compatibility with long lifetime for all components. The invention intracavity conversion to second, third and higher harmonics in several different spectral regimes. The invention also addresses the aspects of design flexibility, seeking in certain embodiments to provide a single platform for providing several harmonic beams.

Abstract: A regenerative amplifier system that is optimized for low-gain gain media is provided. The system is configured to include a minimum number of intra-cavity elements while still eliminating the leakage of the seed pulses from the output beam. In addition, the contrast ratio of the amplified pulses is increased even considering the long build-up time that is required in low-gain regenerative amplifiers. This is accomplished using a single Pockels cell between the oscillator and amplifier to select a single seed pulse for the cavity, instead of using a Faraday isolator. This directs the unwanted seed pulses in a separate direction from the output pulse. When the amplified pulse exits the cavity, it is directed in a direction away from the oscillator by the same Pockels cell. Only one additional Pockels cell and one polarizer are required inside the regenerative amplifier cavity.

Abstract: An optical system has a high power diode pump source and a thin disk gain media. An optical coupler is positioned between the diode pump source and the thin disk gain media. The optical coupler produces a beam with a large numerical aperture incident on the thin disk gain media.

Abstract: An optically pumped laser has a gain medium positioned inside of an optical resonator cavity and disposed about a resonator optical axis. An optical pumping source is positioned outside of the optical resonator cavity. A reflective coupler with a coupler body, and an interior volume passing therethrough is positioned proximal to the optical pumping source. Light from the pumping source passes into an entrance aperture of the reflective coupler to an exit aperture of the reflective coupler positioned distal to the optical pumping source. The interior volume of the reflective coupler is bounded by a reflective surface, an entrance aperture and the exit aperture, and is substantially transparent to radiation from the optical pumping source. The reflective surface has a high reflectivity matched to radiation from the optical pumping source.

Abstract: Wavelength stability of an optical oscillator has been enhanced by feedback from an external position-sensing detector to control the position or tilt of an intracavity optical element, such as a mirror. The wavelength stability results from stabilization of the intracavity beam position relative to an aperture in the oscillator. The wavelength selectivity of the aperture results from incorporation of a dispersive element in the oscillator cavity that produces a mapping of wavelength to beam position at the aperture.

Abstract: A method and system are described aimed at substantially increasing the lifetime of sensitive optical elements subjected to high power laser radiation. The lifetime enhancement is accomplished by spatially distributing the laser beam spots both globally and locally according to algorithms that are custom tailored to the subject element as well as the system and application needs. The methods of the invention are particularly well-suited to non-linear crystals used to convert radiation from high repetition rate, diode-pumped laser systems into the UV spectral range, where lifetime requirements are particularly challenging. The methods of the invention further enable effective utilization of available experimental data characterizing the element's performance in combination with a stored library of preferred spot scanning patterns that may be executed on the surface of the element according to the selected algorithm.

Abstract: An optical system has a diode pump source, and a gain media made of a material with an anisotropic absorption. The gain media is cut at an angle to produce substantially polarization-independent absorption of a pump beam. An optical coupler is positioned between the diode pump source and the gain media. The optical coupler produces a pump beam that has substantially equal amounts of pump power along any two orthogonal axis that are orthogonal to the pump beam in the gain medium. The wavelength range allowed for the pump source is extended.

Abstract: A laser system includes a pump source that produces a first output. The pump source has a feedback loop with a first summing junction and a first command that has step quantization or digitized set point. An output device is coupled to the pump source to receive the first output and produce a second output. A feedback loop is coupled to the first summing junction. The feedback loop includes a second summing junction coupled to at least a portion of the second output. The second summing junction receives a second command and provides an input to the first summing junction. The feedback loop reduces the step quantization from the first output to provide finer control step of a property of the second output.

Abstract: A laser apparatus includes a modelocked laser system with a high reflector and an output coupler that define an oscillator cavity. An output beam is produced from the oscillator cavity. A gain medium and a modelocking device are positioned in the oscillator cavity. A diode pump source produces a pump beam that is incident on the gain medium. A second harmonic generator is coupled to the oscillator cavity. A third harmonic generator that produces a UV output beam, is coupled to the second harmonic generator. A photonic crystal fiber is provided with a proximal end coupled to the laser system. A delivery device is coupled to a distal portion of the photonic crystal fiber.

Abstract: A method and apparatus are provided for in situ protection of sensitive optical materials from alternation or damage due to exposure to trace atmospheric components, during shipping, storage or operation. The sensitive optical material is disposed within an enclosure adaptable to be substantially sealed against the external atmosphere. A container, enclosing a sink material absorbing trace atmospheric components, is coupled to the enclosure by a gas permeable surface, which allows fast diffusion of the trace atmospheric component inside the enclosure to the sink material.

Abstract: An optically pumped laser has a gain medium positioned inside of an optical resonator cavity and disposed about a resonator optical axis. An optical pumping source is positioned outside of the optical resonator cavity. A reflective coupler with a coupler body, and an interior volume passing therethrough is positioned proximal to the optical pumping source. Light from the pumping source passes into an entrance aperture of the reflective coupler to an exit aperture of the reflective coupler positioned distal to the optical pumping source. The interior volume of the reflective coupler is bounded by a reflective surface, an entrance aperture and the exit aperture, and is substantially transparent to radiation from the optical pumping source. The reflective surface has a high reflectivity matched to radiation from the optical pumping source.

Abstract: A diode pumped, multi axial mode, intracavity doubled, intracavity tripled laser, includes at least two resonator mirrors defining a resonator cavity. A laser crystal and a doubling crystal are positioned in the resonator cavity. A tripling crystal is also positioned in the resonator cavity. A diode pump source supplies a pump beam to the laser crystal and produces a laser crystal beam with a plurality of axial modes that are incident on the doubling crystal. This produces a frequency doubled output beam. Further, a diode pumped, multi axial mode, intracavity nonlinearly-converted laser is provided and includes at least two resonator mirrors defining a resonator cavity, a laser crystal and a nonlinear conversion apparatus positioned in the resonator cavity. A nonlinear conversion apparatus is also positioned in the resonator cavity.

Abstract: A diode pumped laser includes a high reflector and an output coupler defining a resonator. The resonator includes a gain medium and a Q-switch and produces a fundamental beam. A first non-linear crystal is positioned extra-cavity of the resonator along a path of the fundamental beam. The first non-linear crystal generates a second harmonic beam from the fundamental beam. The first non-linear crystal is critically phased matched. A second non-linear crystal is portioned extra-cavity of the resonator along a path of the fundamental beam and the path of the second harmonic beam. The second non-linear crystal produces a third harmonic beam. The second non-linear crystal is critically phased matched.

Abstract: An improvement for a vacuum tube or a plasma tube comprises a cathode loop formed of a material suitable for induction heating. A support structure mounted inside the vacuum tube supports the cathode loop at a cathode position. A power supply mounted outside the vacuum tube includes an induction coil wrapped around the tube near the cathode position and generates an alternating electromagnetic field at the cathode position to induce heat in the cathode loop so that electrons are released into the vacuum tube. Finally, a DC bias is applied to the cathode through the support structure. The improved plasma tube with an induction heated cathode is particularly useful for an ion laser gain medium.

Abstract: A Q-switch for a laser having a resonant cavity including an output coupler, a gain medium and a retro-reflecting mirror is mounted in the resonant cavity between the gain medium and the retro-reflecting mirror. The Q-switch comprises a polarizer and a phase retarding element (such as a Pockels cell) which includes a birefringent substrate for inducing a controllable phase retardation in the cavity mode in response to an applied electric field. A tiltable mount supports the phase retarding element so that the lasing axis lies essentially in a plane of the crystallographic axis 45.degree. from the direction of polarization, and lies at an adjustable angle relative to the crystallographic axis. A control circuit supplies an applied electric field within the substrate having a first magnitude in a first state and a second magnitude in a seocnd state. In the first state, the phase retarding element induces 90.degree. rotation in a round trip for the cavity mode.

Abstract: There is disclosed herein an apparatus and method for performing liquid chromatography analysis with a stable baseline. The apparatus utilizes positive displacement means on each of two flow paths and a control system to regulate the flow such that the flow in both flow paths is identical. Only one flow path has sample injected therein. Each flow path is passed through a separate liquid chromatography column and a common detector at the output end of each column. Since one flow path contains solvent only and the other flow path contains both solvent and sample, any changes in the characteristics of the output streams of the liquid chromatography columns caused by changes in the solvent composition itself have a common mode. Therefore, only the difference signal is output from the detector which indicates changes in the characteristics of the output stream of the sample flow path caused solely by the presence of the sample components.

Abstract: There is disclosed herein an apparatus and method for performing liquid chromatography analysis with a stable baseline. The apparatus utilizes positive displacement means on each of two flow paths and a control system to regulate the flow such that the flow in both flow paths is identical. Only one flow path has sample injected therein. Each flow path is passed through a separate liquid chromatography column and a common detector at the output end of each column. Since flow path contains solvent only and the flow path contains both solvent and sample, any changes in the characteristics of the output streams of the liquid chromatography columns caused by changes in the solvent composition itself have a common mode. Therefore, only the difference signal is output from the detector which indicates changes in the characteristics of the output stream of the sample flow path caused solely by the presence of the sample components.

Abstract: There is disclosed herein a modular, high power, flyback transformer based power supply with step up and step down capability. The power supply uses multiple flyback transformers having switching transistors which may be either connected to one terminal of the primary winding or which may be placed in the center of the primary winding. The switching transistors are driven by pulse trains which are out of phase with each other. This results in lowered RMS values for ripple current through the input and output capacitors. The flyback voltage transients may be used to step up or step down the input voltage by varying the pulse width of the pulses in the switching pulse trains. In embodiments where the switching transistors are placed in the middle of the primary windings, better suppression of radio frequency emissions and current in safety ground wires is achieved.