Abstract: A method and apparatus for stabilizing the output of a mode-locked laser by monitoring the temporal behavior of the pulse train profile and controlling the laser cavity optical length and/or loss modulation frequency accordingly. A mismatch of the cavity optical length and the loss modulation frequency will yield a first characteristic noise condition on the laser beam pulse train when the optical length is too short for a given loss modulation frequency and a second, different noise condition when the optical length is too long. The laser beam is monitored and analyzed to determine which noise condition is present. The cavity optical length is adjusted accordingly by movement of one or more optical elements or by changing the index of refraction of one or more optical elements. In the alternative, or additionally, the loss modulation frequency can be adjusted to bring the laser back into mode lock.

Abstract: A multi-headed laser apparatus combining a two or more lasers in a single housing with a single output beam. In addition to the housing, other components can be shared among the lasers such as the power supply, intracavity shutter, and excitation lamp. Additionally, the combination of two or more lasers with different characteristics makes possible a wide range of applications in the areas of materials processing and analysis, among others. A further multi-laser device is disclosed in which the wavelength of one or more of the lasers can be varied.

Abstract: A method and apparatus for stabilizing the output of a mode-locked laser by monitoring the temporal behavior of the pulse train profile and controlling the laser cavity optical length and/or loss modulation frequency accordingly. A mismatch of the cavity optical length and the loss modulation frequency will yield a first characteristic noise condition on the laser beam pulse train when the optical length is too short for a given loss modulation frequency and a second, different noise condition when the optical length is too long. The laser beam is monitored and analyzed to determine which noise condition is present. The cavity optical length is adjusted accordingly by movement of one or more optical elements or by changing the index of refraction of one or more optical elements. In the alternative, or additionally, the loss modulation frequency can be adjusted to bring the laser back into mode lock.

Abstract: A multi-headed laser apparatus combining a two or more lasers in a single housing with a single output beam. In addition to the housing, other components can be shared among the lasers such as the power supply, intracavity shutter, and excitation lamp. Additionally, the combination of two or more lasers with different characteristics makes possible a wide range of applications in the areas of materials processing and analysis, among others. A further multi-laser device is disclosed in which the wavelength of one or more of the lasers can be varied.

Abstract: An apparatus and method to measure optical intensity and phase of one or several light pulses is described. The apparatus combines a spectrally resolved interferometric asymmetric single-shot optical autocorrelator and imaging spectrograph. The asymmetric design of the optical autocorrelator based on second harmonic generation eliminates time-direction ambiguity, while a spectrally resolved interferometric pattern allows the performance of self-check and self-calibration of the apparatus and substantially improves convergence, robustness and reliability of the computational retrieval algorithm.

Abstract: Stackable laser array elements may be configured to absorb heat effectively from laser elements, to be efficiently repaired and/or replaced, and to be effectively tested. An assembly includes readily replaceable cells having a cavity for the passage of coolant therethrough to cool the laser elements. The cells may be constructed individually for individual testing, and then stacked together and removably secured for easy replacement. The cavities of the cells form a substantially contiguous cavity through the entire assembly for the flow of coolant into and out of the assembly. The cavities of the cells include regions and surfaces which enhance the flow of coolant to regions substantially adjacent to the laser elements for the cooling thereof to provide enhanced cooling of the laser elements in the stack of cells. The flow of the coolant is oriented vertically with respect to horizontally oriented laser elements.

Abstract: A method and apparatus pump a laser gain medium of a laser rod having a first longitudinal axis. At least one pump light source emits pump light to the laser rod, and the pump light source has a second longitudinal axis which is perpendicular to the first longitudinal axis. Radiation from various laser diode arrays is collimated and uniquely arranged in a vertical orientation in relation to the laser gain medium. Reflectors focus the collimated radiation from the diode arrays onto the laser gain medium to achieve fundamental mode operation or Transverse Electromagnetic mode (TEM00 mode) operation. Both laser gain medium and reflectors may be simultaneously cooled with appropriate fluids in the apparatus. The assembly of the apparatus may be extended to hold a plurality of vertically oriented laser diode arrays to increase the laser pump power.

Abstract: Intra-cavity and/or inter-cavity sub-resonators with dielectric coated mirrors have anti-reflection and high-reflection coatings to attain high efficiency third and higher order harmonics generation of laser radiation. Main-resonators and sub-resonators enhance the fundamental and harmonic oscillations, respectively, which result in high conversion efficiency of third harmonics and higher. Such improved lasing efficiency may be implemented in high power lasers for improved power performance to attain over 8 W of UV output power with a high repetition rate. The use of intra-cavity THG techniques provide high efficiency by using existing high intensities of the input fundamental frequencies available in the intra-cavity region of the laser to avoid damage to components of the laser, such as the laser crystal. The THG utilizes a double-pass and/or multi-pass arrangement, which results in about a 60% increase in output power compared to a single-pass configuration.