1,721,973 research outputs found
Optical nonlinearity goes ultrafast in 2D semiconductor-based nanocavities
Full text linkHybrid systems of silver nanodisks strongly coupled to monolayer tungsten-disulfide (WS(2)) show giant room-temperature nonlinearity due to their deeply sub-wavelength localized nature, resulting in ultrafast modifications of nonlinear absorption in a solid-state system
Design criteria for ultrafast optical parametric amplifiers
Full text linkOptical parametric amplifiers (OPAs) exploit second-order nonlinearity to transfer energy from a fixed frequency pump pulse to a variable frequency signal pulse, and represent an easy way of tuning over a broad range the frequency of an otherwise fixed femtosecond laser system. OPAs can also act as broadband amplifiers, transferring energy from a narrowband pump to a broadband signal and thus considerably shortening the duration of the pump pulse. Due to these unique properties, OPAs are nowadays ubiquitous in ultrafast laser laboratories, and are employed by many users, such as solid state physicists, atomic/molecular physicists, chemists and biologists, who are not experts in ultrafast optics. This tutorial paper aims at providing the non-specialist reader with a self-consistent guide to the physical foundations of OPAs, deriving the main equations describing their performance and discussing how they can be used to understand their most important working parameters (frequency tunability, bandwidth, pulse energy/repetition rate scalability, control over the carrier-envelope phase of the generated pulses). Based on this analysis, we derive practical design criteria for OPAs, showing how their performance depends on the type of the nonlinear interaction (crystal type, phase-matching configuration, crystal length), on the characteristics of the pump pulse (frequency, duration, energy, repetition rate) and on the OPA architecture
Apparato per la fabbricazione di dispositivi fotonici con impulsi laser ultrabrevi e realtivo metodo di fabbricazione
No full textApparato per la fabbricazione di dispositivi fotonici con impulsi laser ultrabrevi e realtivo metodo di fabbricazion
Structural dynamics LEEDS the way
No full textTracking the momentum of scattered electrons reveals the temporal evolution of phonon populations on ultrafast timescales, helping to quantify the contributions of the cooperative electronic–lattice order responsible for phase transitions in quantum materials
Phase - locked delay device including an optical wedge pair
No full textA phase-locked delay device, including: an input port configured to receive an input electromagnetic radiation pulse; said input pulse being to be propagated along a propagation direction and having a first linear polarization different from both a first direction, which is orthogonal to the propagation direction, and a second direction, which is orthogonal to the first direction and the propagation direction;an adjustable Babinet-Soleil module optically coupled to said input port, having a first polarization direction parallel to said first direction. The adjustable Babinet-Soleil module is structured to: provide from the input pulse a first pulse polarized along the first direction and a second pulse collinear to said first pulse and polarized along the second direction, and introduce an adjustable group delay between the first pulse and the second pulse ranging from a minim value ΔTm and a maximum value ΔTM; the maximum value ΔTM being a value greater than 10 fs
Group velocity mismatch compensation in cw lasers mode-locked by second order nonlinearities
No full textPhase-locked pulses for two-dimensional spectroscopy by a birefringent delay line
No full textWe introduce the translating wedge-based identical pulses encoding system, a novel device for the generation of collinear, interferometrically locked ultrashort pulse pairs. By means of birefringent wedges, we are able to control the pulse delay with attosecond precision and stability better that lambda/360, without affecting the pulse duration and in a spectral range that spans from UV to mid-IR. This device is expected to dramatically simplify two-dimensional spectroscopy experiments. (C) 2012 Optical Society of Americ
Space-time coupling and collapse threshold for femtosecond pulses in dispersive nonlinear media
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