Probing the fluctuating vacuum According to quantum mechanics, a is not empty space. A consequence of uncertainly principle that particles or energy can come into existence for fleeting moment. Such fluctuations are known exist, but evidence them has been indirect. Riek et al. present an ultrafast optical based technique probes fluctuation electromagnetic radiation directly. Science , this issue p. 420

Abstract A nonlinear optical platform is presented to emulate a Lévy waveguide that supports the pulse propagation governed by generalized fractional Schrödinger equation (FNLSE). This approach distinguishes between intra‐cavity and extra‐cavity regimes, exploring interplay effective group‐velocity dispersion (FGVD) Kerr nonlinearity. In configuration, stable solitons enabled an engineered combination of regular dispersions in fiber cavity are observed. The soliton pulses exhibit their...

This review discusses the progress and ongoing efforts in optical refrigeration. Optical refrigeration is a process which phonons are removed from solid by anti-Stokes fluorescence. The first summarizes history of refrigeration, noting success cooling rare-earth-doped solids to cryogenic temperatures. It then examines detail four-level model rare-earth-based elucidates essential roles that various material parameters, such as spacing energy levels radiative quantum efficiency, play describes...

We report on bulk optical refrigeration of Yb:YLF crystal to a temperature ∼124 K, starting from the ambient. This is achieved by pumping E4-E5 Stark multiplet transition at ∼1020 nm. A lower 119±1 K (∼−154C) with available cooling power 18 mW attained when surrounding reduced 210 K. result within only few degrees minimum achievable our and signifies solid-state laser below National Institute Standards Technology (NIST)-defined cryogenic 123

We review the field of laser cooling solids, focusing our attention on recent advances in cryogenic an ytterbium-doped fluoride crystal (Yb3+:YLiF4). Recently, bulk this material to 155 K has been observed upon excitation near lowest-energy (E4–E5) crystal-field resonance Yb3+. Furthermore, local same a minimum achievable temperature 110 measured, agreement with predictions model. This value is limited only by current purity. Advanced synthesis approaches reviewed here would allow reaching...

Systematic study of Yb doping concentration in the Yb:YLF cryocoolers by means optical and mass spectroscopies has identified iron ions as main source background absorption.Parasitic absorption was observed to decrease with doping, resulting cooling a 10% sample 114K ± 1K, room temperature power 750 mW calculated minimum achievable 93 K.

Abstract High-harmonic generation has been driving the development of attosecond science and sources. More recently, high-harmonic in solids adopted by other communities as a method to study material properties. However, so far only driven classical light, despite theoretical proposals do with quantum states light. Here we observe non-perturbative macroscopic state bright squeezed vacuum, which generate single spatiotemporal mode. The process vacuum is considerably more efficient high...

We observe intense pulses of far-infrared electromagnetic radiation emitted from arrays InAs nanowires. The THz power efficiency these structures is about 15 times higher compared to a planar substrate. This explained by the preferential orientation coherent plasma motion wire surface, which overcomes trapping total-internal reflection. present evidence that this originates low-energy acoustic surface plasmon mode nanowire. supported independent measurements electronic transport on...

Minimum achievable temperature of ~110 K is measured in a 5% doped Yb:YLF crystal at λ = 1020 nm, corresponding to E4-E5 resonance Stark manifold. This measurement excellent agreement with the laser cooling model and was made possible by employing novel sensitive implementation differential luminescence thermometry using balanced photo-detectors.

Direct detection of vacuum fluctuations and analysis subcycle quantum properties the electric field are explored by a paraxial theory ultrafast electro-optic sampling. The feasibility such experiments is demonstrated realistic calculations adopting thin ZnTe crystal stable few-femtosecond laser pulses. We show that nonlinear mixing short near-infrared probe pulse with multiterahertz leads to an increase signal variance respect shot noise level. contribution increases significantly for...

We present analytical considerations of "self-mode-locked" operation in a typical vertical external-cavity surface-emitting laser (VECSEL) cavity geometry by means Kerr lens action the semiconductor gain chip.We predict Kerr-lens mode-locked for both soft-and hard-apertures placed at optimal intra-cavity positions.These predictions are experimentally verified VECSEL capable producing pulse durations below 500 fs 1 GHz repetition rate.

We demonstrate time-domain sampling of mid-infrared electric field transients and their conjugate counterparts exploiting the dynamical Pockels effect. To this end, complete polarization change few-femtosecond probe pulses is studied. An intuitive picture based on a phasor representation established before gaining quantitative understanding in experiment theory. In standard version electro-optic sampling, determined by analyzing ellipticity polarization. Beyond this, we find that temporal...

We observe non-perturbative high harmonic generation in solids driven by a macroscopic quantum state of light, bright squeezed vacuum (BSV), which we generate single spatiotemporal mode. The BSV-driven process is considerably more efficient the harmonics than classical light same mean intensity. Due to its broad photon-number distribution, covering states from $0$ $2 \times 10^{13}$ photons per pulse, and sub-cycle electric field fluctuations over $\pm1\hbox{V}/\hbox{\r{A}}$, BSV provides...

We review the recent progress in experimental and theoretical research of interactions between acoustic, magnetic plasmonic transients hybrid metal-ferromagnet multilayer structures excited by ultrashort laser pulses. The main focus is on understanding nonlinear aspects acoustic dynamics materials as well peculiarities optical magneto-optical response. For example, detection illustrated details probing static second harmonic generation gold-cobalt-silver trilayer Kretschmann geometry....

We demonstrate laser induced cooling in ytterbium doped silica (SiO2) glass with alumina, yttria co-doping (GAYY-Aluminum: Yttrium: Ytterbium Glass) fabricated using the modified chemical vapour deposition (MCVD) technique. A maximum temperature reduction by - 0.9 K from room (296 K) at atmospheric pressure was achieved only 6.5 W of 1029 nm radiation. The developed fabrication process allows us to incorporate concentration 4 × 1026 ions/m3 which is highest value reported for without...

Abstract Nonlinear optical methods, such as Electric-Field Induced Second Harmonic (E-FISH) generation, have emerged powerful tools for diagnosing electric fields in plasma environments. The E-FISH technique depends quadratically on the field under study, which results complete insensitivity to its polarity and diminished sensitivity low amplitudes. Both of these challenges been recently resolved a Local Oscillator (LOE-FISH) technique, introducing coherent homodyne amplification weak signal...

Optical frequency combs based on erbium-doped fiber lasers are attractive tools in precision metrology due to their inherent compactness and stability.Here we study a femtosecond Er:fiber comb that passively eliminates the carrierenvelope phase slip by difference generation.Quantum statistics inside all-fiber soliton oscillator governs its free-running performance.Active stabilization of repetition rate supports subhertz optical linewidth does not necessitate additional intracavity...

Vibration-free cooling of detectors to cryogenic temperatures is critical for many terrestrial, airborne, and space-based instruments. Cooling solids by anti-Stokes fluorescence an emerging refrigeration technology that inherently vibration-free compact, enables small loads temperatures. In this Highlight, advances in laser-cooling are discussed with a particular focus on the recent breakthrough laser Yb3+-doped YLiF4 crystals 114 K. The importance material structure, composition, purity...