1,721,016 research outputs found
The importance of Rydberg orbitals in dissociative ionization of small hydrocarbon molecules in intense few-cycle laser pulses
Full text linkCitation: Jochim, B., Siemering, R., Zohrabi, M., Voznyuk, A., Mahowald, J. B., Schmitz, D. G., . . . De Vivie-Riedle, R. (2015). The importance of Rydberg orbitals in dissociative ionization of small hydrocarbon molecules in intense few-cycle laser pulses. 635(11). doi:10.1088/1742-6596/635/11/112043We demonstrate the importance of ionization from Rydberg orbitals via experimental and theoretical work focusing on the strong-field dissociative single ionization of small hydrocarbons. Our findings suggest that Rydberg states should be routinely considered when studying polyatomic molecules in intense laser fields. © Published under licence by IOP Publishing Ltd.Additional Authors: Wells, E.;De Vivie-Riedle, R
Tuning of isomerization rates in indigo-based photoswitches
No full textUltrafast excited-state dynamics in indigo-based photochromic compounds was studied with the transient absorption spectroscopy and ab initio calculations. We demonstrate an approach for adjusting excited state relaxation routesand photoisomerization rates for applications where fast photoswitching is needed
Ultrafast energy flow and equilibration dynamics in photosynthetic light-harvesting complexes
No full textWe disentangle various energy transfer pathways in the bacterio-chlorophyll excitation cascade from LH2 to LH1 in Chromatium vinosum grown under high-light or low-light illumination using tunable narrowband selective excitation and broadband infrared probing
Towards optical attosecond pulses: broadband phase coherence between an ultrafast laser and OPO using lock-tozero CEO stabilization
No full textThe carrier-envelope-offset frequencies of the pump, signal, idler and related sum-frequency mixing pulses have been locked to 0 Hz in a 20-fs-Ti:sapphire-pumped optical parametric oscillator, satisfying a critical prerequisite for optical attosecond pulse synthesis
π-Conjugated Donor-Acceptor Systems as Metal-Free Sensitizers for Dye-Sensitized Solar Cell Applications
Full text linkHigh extinction coefficients and easily tunable spectral properties of π- conjugated donor-acceptor dyes are of superior advantage for the design of new metalfree organic sensitizers for applications in dye-sensitized solar cells. Ultrafast transient absorption spectroscopy on the femtosecond and nanosecond time scales provided deep insights into the dependence of charge carrier dynamics in fully organic dye/TiO2 systems on i) the donor-acceptor distance, ii) the π-conjugation length, and iii) the coupling to TiO2 by different anchoring groups. Importantly, the observed differences in charge transfer dynamics justify the variations of photovoltaic performances of the dyes as applied in solar cell devices. This leads to the conclusion that the photoconversion efficiencies strongly depend on a delicate interplay between the dyes’ building blocks, i.e. the donor, the π-conjugated spacer and the anchor/acceptor moieties, and may easily be tuned by molecular design
Asynchronous mid-infrared broadband optical parametric oscillator for dual-comb spectroscopy
No full textTwo asynchronous, broadband 3.3-mu m pulse trains with a stabilized repetition-rate difference of up to 5-kHz were generated from a single optical parametric oscillator. With additional carrier-envelope-offset stabilization, it could be applied to coherent dual-frequency-comb spectroscopy.</p
Highly-efficient 1-GHz-repetition-frequency femtosecond Yb3+:KY(WO4)2 laser for super-continuum generation
No full textWe present a 1.024-GHz-repetition-rate femtosecond Yb3+:KY(WO4)2 laser with 61% optical-to-optical efficiency and 69% slope efficiency, generating a supercontinuum of bandwidth 400 nm in silica photonic-crystal fibre. RIN measurements of the laser yielded values <0.1%
Femtosecond pulse generation at 50 W average powers from an Yb:KYW-Yb:YAG planar-waveguide MOPA
No full textAn Yb:YAG planar-waveguide power amplifier seeded by an Yb:KYW master oscillator is reported. The system produced 700-fs pulses at 1032 nm at average output powers of 50 W and a frequency of 53 MHz.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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