253 J at 0.2 Hz, LD pumped cryogenic helium gas cooled Yb:YAG ceramics laser.

A 253 J with 26 ns at 0.2 Hz laser performance was demonstrated using a LD pumped cryogenically cooled Yb:YAG ceramics laser amplifier. A high energy storage of 344 J was achieved with a stored energy density of 0.

Broadband mid-infrared amplified spontaneous emission from Er/Dy co-doped fluoride fiber with a simple diode-pumped configuration.

Er/Dy co-doped double-clad ZBLAN optical fiber has been used to obtain amplified spontaneous emission (ASE) broadband light sources cladding-pumped by 980-nm multimode laser diode (LD) sources. It has been demonstrated that mid-infrared broadband emission extending from 2515 to 3735 nm was obtained by energy transfer between Er and Dy. We experimentally investigated the optimum design of Er/Dy co-doped ZBLAN fiber in terms of ion concentration, fiber length, pumping configuration, and pumping power.

10 J operation of a conductive-cooled Yb:YAG active-mirror amplifier and prospects for 100 Hz operation.

We report, to the best of our knowledge, the highest power conductive-cooled active-mirror amplifier (CcAMA) using Yb:YAG with a pulse energy of 10 J. By using four liquid-nitrogen circulating cooled laser heads, we achieved a repetition rate, pulse energy, and average power of 33.3 Hz, 9.

40 kHz, 20 ns acousto-optically Q-switched 4 µm Fe:ZnSe laser pumped by a fluoride fiber laser.

An actively -switched mid-infrared Fe:ZnSe laser pumped by a continuous wave fluoride fiber laser has been developed. Stable operation with a pulse duration of 20 ns and a repetition rate of 40 kHz at 4 µm was achieved. The maximum peak power was 1.

Power scalable 30-W mid-infrared fluoride fiber amplifier.

A fluoride-fiber-based master oscillator power amplifier (MOPA) for 30-W class continuous-wave (cw) operation at 2.8-μm wavelength has been demonstrated. To overcome the low durability of ZBLAN fibers, various novel technologies for using fluoride glass with a ZBLAN-fiber-based side-pump combiner have been adopted in the system.

Arbitrarily distorted 2-dimensional pulse-front measurement and reliability analysis.

A method of 2-dimensional (2-D) space-scanned (in the x-y plane) spatiotemporal double-slit interference is used to reconstruct the 2-D pulse-front (in the x-y-t domain) of a femtosecond pulsed beam. While comparing with recent other methods, the method possesses two advantages: no reference pulse/beam is required anymore, and an arbitrarily distorted pulse-front, not just pulse-front tilt and pulse-front curvature, could be detected. Meanwhile, the influence of different factors of unknown pulsed beams and optical elements on the measurement reliability is also analyzed for engineering applications.

Plane-by-plane femtosecond laser inscription of first-order fiber Bragg gratings in fluoride glass fiber for in situ monitoring of lasing evolution.

We report the femtosecond laser inscription of fiber Bragg gratings (FBGs) in an Er-doped fluoride glass fiber used for lasing at a mid-infrared wavelength of 2.8 µm. The lasing evolution is discussed in terms of the FBG reflectivity, wavelength transition to the Bragg wavelength, and output power of the mid-infrared fiber laser.

High beam quality and high peak power Yb:YAG/Cr:YAG microchip laser.

The prospect for developing a passively Q-switched Yb:YAG/Cr:YAG monolithic microchip laser that operates at cryogenic temperature is theoretically analyzed. It is concluded that such a system has the potential to deliver laser pulses with improved energy and increased peak power in comparison with composite Yb:YAG/Cr:YAG or Nd:YAG/Cr:YAG devices that are operated at room temperature. Consequently, a cryogenically cooled Yb:YAG/Cr:YAG system is built and the emission performances are investigated.

Stable ultra-broadband gain spectrum with wide-angle non-collinear optical parametric amplification.

Comparing with the non-collinear optical parametric amplification (NOPA), the gain bandwidth could be significantly enhanced by the wide-angle NOPA (WNOPA), i.e., with a divergent signal (WNOPA-S) or pump (WNOPA-P).

Magnetized fast isochoric laser heating for efficient creation of ultra-high-energy-density states.

Fast isochoric heating of a pre-compressed plasma core with a high-intensity short-pulse laser is an attractive and alternative approach to create ultra-high-energy-density states like those found in inertial confinement fusion (ICF) ignition sparks. Laser-produced relativistic electron beam (REB) deposits a part of kinetic energy in the core, and then the heated region becomes the hot spark to trigger the ignition. However, due to the inherent large angular spread of the produced REB, only a small portion of the REB collides with the core.

PCSEL pumped coupling optics free Yb:YAG/Cr:YAG microchip laser.

The passively Q-switched operation of a cryogenically cooled Yb:YAG/Cr:YAG microchip laser was demonstrated with end pumping by a photonic crystal surface emitting laser (PCSEL). This laser generated 70 μJ/1.7 ns/3.

Actively Q-switched dual-wavelength pumped Er :ZBLAN fiber laser at 3.47 µm.

We demonstrate the first actively Q-switched fiber laser operating in the 3.5 μm regime. The dual-wavelength pumped system makes use of an Er doped ZBLAN fiber and a germanium acousto-optic modulator.

Induction of subterahertz surface waves on a metal wire by intense laser interaction with a foil.

We have demonstrated that a pulsed electromagnetic wave (Sommerfeld wave) of subterahertz frequency and 11-MV/m field strength can be induced on a metal wire by the interaction of an intense femtosecond laser pule with an adjacent metal foil at a laser intensity of 8.5×10^{18}W/cm^{2}. The polarity of the electric field of this surface wave is opposite to that obtained by the direct interaction of the laser with the wire.

Optimization of laser emission at 2.8 μm by Er:LuO ceramics.

We have demonstrated the continuous-wave operation of a highly efficient 2.8 μm Er-doped LuO ceramic laser at room temperature. An Er:LuO ceramic with a doping concentration of 11 at.

12 mJ Yb:YAG/Cr:YAG microchip laser.

We have developed a quasi-continuous wave diode end-pumped cryogenically cooled Yb:YAG/Cr:YAG passively Q-switched microchip laser. A maximum energy of 12.1 mJ with 3.

Scattering pulse-induced temporal contrast degradation in chirped-pulse amplification lasers.

Herein, a theory for modeling the problem of scattering pulse-induced temporal contrast degradation in chirped-pulse amplification (CPA) lasers is introduced. Using this model, the temporal evolutions of the scattering and signal pulses were simulated, the temporal contrasts for different cases were compared, and finally the theoretical prediction was verified by an experimental demonstration. The result shows that the picosecond and the nanosecond temporal contrast is mainly determined by the scattering pulses generated in the stretcher and the compressor, respectively.

Generation of 300 nm bandwidth 0.5 mJ pulses near 1 μm in a single stage gas filled hollow core fiber.

A simple and compact spectral-broadening system is presented that is based on a single-stage statically pressurized Ar filled hollow core fiber. By optimizing the inner diameter of the hollow core fiber, a bandwidth of 300 nm is obtained. This is the broadest bandwidth known to date with millijoule level energy near the 1-μm wavelength by a single stage gas filled hollow core fiber.

Efficient continuous wave and quasi-continuous wave operation of a 2.8 μm Er:LuO ceramic laser.

We have demonstrated a highly efficient 2.8 μm Er-doped LuO ceramic laser and investigated the lasing dynamics by time-resolved spectroscopy. During room-temperature continuous wave operation, a slope efficiency of 22% was achieved with a high-quality transparent ceramic.

Cryogenically cooled CeF3 crystal as media for high-power magneto-optical devices.

The thermally induced depolarization and Verdet constant of CeF crystals-their most important characteristics-have been studied in the 79-293 K temperature range. It has been found that thermal effects reduce substantially upon cooling down to 79 K and the Verdet constant grows in inverse proportion to the temperature. It was shown that CeF crystals are not inferior to TGG as a medium for Faraday isolators, including cryogenic ones.

Demonstration of a photonic crystal surface-emitting laser pumped Yb:YAG laser.

We developed a cryogenically cooled Yb:YAG continuous wave oscillator directly pumped with a photonic crystal surface-emitting laser (PCSEL). A high slope efficiency of 65.7% was obtained at an output power of 208 mW.

Single plasma mirror providing 10 contrast enhancement and 70% reflectivity for intense femtosecond lasers: publisher's note.

This note points out a missed correction to the math on p. 5648 of [Appl. Opt.

Single plasma mirror providing 10 contrast enhancement and 70% reflectivity for intense femtosecond lasers.

To efficiently eliminate picosecond pre-pulses that accompany ultrashort pulses emitted from high-power chirped-pulse-amplification laser systems, we have developed a high-performance plasma mirror system. By reducing the reflectivity of the antireflection coating on the substrate for the plasma mirror to the limit of current technology (∼0.006%), we achieved the highest pre-pulse contrast enhancement reported to date for a single plasma mirror of 10 at 1 ps before the pulse peak.

Heating efficiency evaluation with mimicking plasma conditions of integrated fast-ignition experiment.

A series of experiments were carried out to evaluate the energy-coupling efficiency from heating laser to a fuel core in the fast-ignition scheme of laser-driven inertial confinement fusion. Although the efficiency is determined by a wide variety of complex physics, from intense laser plasma interactions to the properties of high-energy density plasmas and the transport of relativistic electron beams (REB), here we simplify the physics by breaking down the efficiency into three measurable parameters: (i) energy conversion ratio from laser to REB, (ii) probability of collision between the REB and the fusion fuel core, and (iii) fraction of energy deposited in the fuel core from the REB. These three parameters were measured with the newly developed experimental platform designed for mimicking the plasma conditions of a realistic integrated fast-ignition experiment.

Transient changes in electric fields induced by interaction of ultraintense laser pulses with insulator and metal foils: Sustainable fields spanning several millimeters.

The temporal evolutions of electromagnetic fields generated by the interaction between ultraintense lasers (1.3×10(18) and 8.2×10(18)W/cm(2)) and solid targets at a distance of several millimeters from the laser-irradiated region have been investigated by electron deflectometry.