Demonstration of a 1 TW peak power, joule-level ultrashort Tm:YLF laser.

We report on the demonstration of a diode-pumped, Tm:YLF-based, chirped pulse amplification laser system operating at λ ≈ 1.9 µm that produces amplified pulse energies exceeding 1.5 J using a single 8-pass power amplifier.

1 GW peak power and 100 J pulsed operation of a diode-pumped Tm:YLF laser.

We report on the generation of high energy, high power pulses in a tabletop diode-pumped Tm:YLF-based laser system, which delivers amplified pulse energies up to 108 J, as well as GW peak power performance when seeded with nanosecond duration pulses. Furthermore, the high power and efficiency capabilities of operating Tm:YLF in the multi-pulse extraction (MPE) regime were explored by seeding the experimental setup with a multi-kHz burst of pulses exhibiting a low individual pulse fluence, resulting in a 3.6 kW average power train of multi-joule-level pulses with an optical-to-optical efficiency of 19%.

Femtosecond damage experiments and modeling of broadband mid-infrared dielectric diffraction gratings.

High peak and average power lasers with high wall-plug efficiency, like the Big Aperture Thulium (BAT) laser, have garnered tremendous attention in laser technology. To meet the requirements of the BAT laser, we have developed low-dispersion reflection multilayer dielectric (MLD) gratings suitable for compression of high-energy pulses for operations at 2 micron wavelength. We carried out 10000-on-1 damage tests to investigate the fluence damage thresholds of the designed MLD gratings and mirrors, which were found between 100-230 mJ/cm.

Demonstration of a compact, multi-joule, diode-pumped Tm:YLF laser.

We report the demonstration of a diode-pumped Tm:YLF laser operating at 1.88 µm that produces pulse energies up to 3.88 J in 20 ns.

1.1 J Yb:YAG picosecond laser at 1 kHz repetition rate.

We demonstrate the generation of 1.1 J pulses of picosecond duration at 1 kHz repetition rate (1.1 kW average power) from a diode-pumped chirped pulse amplification Yb:YAG laser.

Laser induced damage in coatings for cryogenic Yb:YAG active mirror amplifiers.

We report results of a study of the laser induced damage threshold (LIDT) behavior of ion beam sputtered / multilayer coatings on Yb:YAG using 1-on-1 and N-on-1 test protocols. The tests were conducted at ambient, vacuum, and cryogenic conditions using 280 ps pulses at =1030. The 1-on-1 LIDT of antireflection (AR) stacks is found to be only slightly reduced under vacuum and cryogenic conditions, while that of high reflectivity (HR) stacks is insensitive to environmental conditions within the uncertainty of the measurements.

Programmable pulse synthesizer for the generation of Joule-level picosecond laser pulses of arbitrary shape.

We report the demonstration of a pulse synthesizer based on spatial beam splitting and pulse stacking for the generation of picosecond laser pulses of Joule-level energy with arbitrary shape. An array of liquid crystals is used to control the amplitude of ten individual sub-pulses, and sliding retroreflectors are used to adjust their temporal separations. The synthesizer was used in combination with a λ=1.

In situ 3-D temperature mapping of high average power cryogenic laser amplifiers.

Heat generation is a key obstacle to scaling high energy solid-state lasers to the multi-kilowatt average powers required for several key applications. We demonstrate an accurate, in situ, noninvasive optical technique to that makes three-dimensional (3-D) temperature maps within cryogenic amplifiers operating at high average power. The temperature is determined by analyzing the fluorescence spectra with a neural network function.

Strategies to increase laser damage performance of TaO/SiO mirrors by modifications of the top layer design.

TaO/SiO high reflection (HR) interference coatings for λ∼1  μm offer superior performance at high irradiance conditions. However, these coatings are not good candidates for high peak power conditions in comparison to HfO/SiO multilayer stacks. Here we show that the modification of the top layers design of a quarter wave TaO/SiO high reflector leads to 4-5 fold increase in the laser damage fluence compared to a quarter wave (TaO/SiO) when tested at λ=1.

1 J, 0.5 kHz repetition rate picosecond laser.

We report the demonstration of a diode-pumped chirped pulse amplification Yb:YAG laser that produces λ=1.03  μm pulses of up to 1.5 J energy compressible to sub-5 ps duration at a repetition rate of 500 Hz (750 W average power).

Hour-long continuous operation of a tabletop soft x-ray laser at 50-100 Hz repetition rate.

We report the uninterrupted operation of an 18.9 nm wavelength tabletop soft x-ray laser at 100 Hz repetition rate for extended periods of time. An average power of about 0.

Demonstration of a 100 Hz repetition rate gain-saturated diode-pumped table-top soft x-ray laser.

We demonstrate the operation of a gain-saturated table-top soft x-ray laser at 100 Hz repetition rate. The laser generates an average power of 0.15 mW at λ=18.

Comparison of 30-day outcomes of coronary artery bypass grafting surgery verus hybrid coronary revascularization stratified by SYNTAX and euroSCORE.

Objective: The optimal treatment of multivessel coronary artery disease is not well established. Hybrid coronary revascularization by combining the left internal mammary artery-left anterior descending artery graft and drug-eluting stents in non-left anterior descending artery territories might offer superior results compared with sole coronary artery bypass grafting or sole percutaneous coronary intervention.

Methods: We retrospectively analyzed the 30-day outcomes of 381 consecutive patients undergoing coronary artery bypass grafting (n = 301) vs hybrid coronary revascularization (n = 80).

Emerging applications of nanotechnology for the diagnosis and management of vulnerable atherosclerotic plaques.

An estimated 16 million people in the United States have coronary artery disease (CAD), and approximately 325,000 people die annually from cardiac arrest. About two-thirds of unexpected cardiac deaths occur without prior recognition of cardiac disease. A vast majority of these deaths are attributable to the rupture of 'vulnerable atherosclerotic plaques'.

Demonstration of an all-diode-pumped soft x-ray laser.

We have demonstrated an 18.9 nm Ni-like molybdenum soft x-ray laser, pumped by a compact all-diode-pumped Yb:YAG laser. The solid-state pump laser produces 8.

High-order harmonic generation from ions in a capillary discharge.

We demonstrate a significant extension of the high-order harmonic cutoff by using a fully-ionized capillary discharge plasma as the generation medium. The preionized plasma dramatically reduces ionization-induced defocusing and energy loss of the driving laser due to ionization. This allows for significantly higher photon energies, up to 150 eV, to be generated from xenon ions, compared with the 70 eV observed previously.