An efficient, compact source of coherent radiation in the infrared, visible and ultraviolet portion of the spectrum which is capable of modulation rates over the range from O Hz to in excess of 1 GHz. The radiation is produced by optical mixing within an external optical cavity wherein at least one of the interacting beams of light is provided by a solid state device selected from the group consisting of laser diodes, laser diode arrays and diode-pumped solid state lasers.

Generation of coherent optical radiation by optical mixing

An efficient, compact source of coherent radiation in the infrared, visible and ultraviolet portion of the spec­trum which is capable of modulation rates over the range from 0 Hz to in excess of 1 GHz. The radiation is pro­duced by optical mixing within the optical cavity of a laser by introducing input radiation into the optical cavity where: (a) the cavity is that of a diode-pumped solid state laser, and/or (b) input radiation is provided by a solid state device selected from the group consisting of laser diodes, laser diode arrays and diode-pumped solid state lasers.

Intracavity generation of coherent optical radiation by optical mixing

Picosecond and femtosecond pulses provide a unique tool for the study of ultra-fast processes accompanying light-matter interaction. Novel measuring techniques, on the one hand, expanded the experimental capabilities in this field while, on the other hand, a great demand for suitable pulses in various spectral regions was created that cannot be directly fulfilled by available laser systems. A basic solution of this problem is offered by quantum optics which can convert pulse frequencies with the help of nonlinear optical effects. A second motivation for the study of short pulse nonlinearities is the high power level necessarily connected with shorter and shorter pulses of finite energy content. Consequently, nonlinear effects cannot be ignored in spectroscopic applications for an adequate understanding of the coupling between the short pulse and the dynamical processes under investigation. Without exaggeration one can say that nonlinear optics is an inherent and fundamental part of the generation, analysis and application of ultrashort laser pulses.

Optical nonlinearities with ultrashort pulses

Operando characterization plays an important role in revealing the structure-property relationships of organic mixed ionic/electronic conductors (OMIECs), enabling the direct observation of dynamic changes during device operation and thus guiding the development of new materials. This review focuses on the application of different operando characterization techniques in the study of OMIECs, highlighting the time-dependent and bias-dependent structure, composition, and morphology information extracted from these techniques. We first illustrate the needs, requirements, and challenges of operando characterization then provide an overview of relevant experimental techniques, including spectroscopy, scattering, microbalance, microprobe, and electron microscopy. We also compare different in silico methods and discuss the interplay of these computational methods with experimental techniques. Finally, we provide an outlook on the future development of operando for OMIEC-based devices and look toward multimodal operando techniques for more comprehensive and accurate description of OMIECs.

https://pubs.acs.org/doi/pdf/10.1021/acs.chemrev.1c00597

Operando Characterization of Organic Mixed Ionic/Electronic Conducting Materials.

Laser-direct drive (LDD), along with laser indirect (X-ray) drive (LID) and magnetic drive with pulsed power, is one of the three viable inertial confinement fusion approaches to achieving fusion ignition and gain in the laboratory. The LDD programme is primarily being executed at both the Omega Laser Facility at the Laboratory for Laser Energetics and at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. LDD research at Omega includes cryogenic implosions, fundamental physics including material properties, hydrodynamics and laser-plasma interaction physics. LDD research on the NIF is focused on energy coupling and laser-plasma interactions physics at ignition-scale plasmas. Limited implosions on the NIF in the 'polar-drive' configuration, where the irradiation geometry is configured for LID, are also a feature of LDD research. The ability to conduct research over a large range of energy, power and scale size using both Omega and the NIF is a major positive aspect of LDD research that reduces the risk in scaling from OMEGA to megajoule-class lasers. The paper will summarize the present status of LDD research and plans for the future with the goal of ultimately achieving a burning plasma in the laboratory. This article is part of a discussion meeting issue 'Prospects for high gain inertial fusion energy (part 2)'.

Direct-drive laser fusion: status, plans and future.

We report a new Nd:YAG-pumped picosecond optical parametric oscillator that generates bandwidth-limited pulses. Using two LiNbO3 crystals, it produces tunable, near-1.4-μm (signal-wave) pulses of 18-psec duration and Δν = 1.2 cm−1 FWHM (Δντ = 0.7). The output energy of the optical parametric oscillator in a signal wave is no less than 2 mJ with 10% energy stability. The key to this device is the injection of cw single-frequency GaAs diode-laser radiation. Using the injection of diode-laser radiation, we have measured the spectral intensity of a quantum noise at λ = 0.85 μm. The intensity was found to be 6 ± 2 W/cm2 cm−1 sr (theoretical value, 4.7 W/cm2 cm−1 sr).

S. D. Yakubovich

Papers

Generation of bandwidth-limited tunable picosecond pulses by injection-locked optical parametric oscillators.