The dissociative ionization of ethanol C2H5OH in an intense laser field is investigated with a chirped laser pulse. From the sensitive dependence of the relative yields of the fragment ions on the absolute values of the linear chirp rate, it is shown that the light-dressed potential-energy surface (LDPES) at the singly charged stage governs the nuclear dynamics, and that the nuclear wave packet flow into the breaking of either of the C–C and C–O chemical bonds could be characterized by the holding time thold during which the LDPESs are maintained. It is also understood in term of the holding time that the enhanced ionization into the doubly charged stage followed by the Coulomb explosion at C–C or C–O proceeds when the nuclear wave packet at the singly charged stage reaches the critical distance for the further ionization.
The relative yield of the C-O bond breaking with respect to the C-C bond breaking in ethanol cation C2H5OH+ is maximized in intense laser fields (10(13)-10(15) Wcm2) by open-loop and closed-loop optimization procedures. In the open-loop optimization, a train of intense laser pulses are synthesized so that the temporal separation between the first and last pulses becomes 800 fs, and the number and width of the pulses within a train are systematically varied. When the duration of 800 fs is filled with laser fields by increasing the number of pulses or by stretching all pulses in a triple pulse train, the relative yield of the C-O bond breaking becomes significantly large. In the closed-loop optimization using a self-learning algorithm, the four dispersion coefficients or the phases of 128 frequency components of an intense laser pulse are adopted as optimized parameters. From these optimization experiments it is revealed that the yield ratio of the C-O bond breaking is maximized as far as the total duration of the intense laser field reaches as long as approximately 1 ps and that the intermittent disappearance of the laser field within a pulse does not affect the relative yields of the bond breaking pathways.
High throughput printing processes have been developed for the fabrication of organic flexible sheet devices. However, printing processes inevitably use toxic solvents to prepare inks of organic semiconductors. Here we propose a novel and complementary method for the preparation of flexible sheet electronics. A thermal pressing method has several advantages, such as (i) being solvent-free, (ii) resulting in flexible device with structural durability against bending, (iii) making simultaneous sealing available to prevent physical or atmospheric damage, and (iv) providing seamless application to roll-to-roll processes by combination with toner technology. We have demonstrated that the characteristics of a flexible organic field-effect transistor (OFET) fabricated by the thermal press process were not degraded during or after the bending test until a bending radius of 2 mm was achieved, which is sufficient for the concept of a rolled-up type flexible sheet display.
We propose a novel and complementary method for fabrication of flexible electronics. This method is not based on conventional printing using inks, but is based on the application of a toner‐based method such as Xerox or laser printing, followed by a lamination process. The lamination method is a solvent‐free and material‐saving process that simultaneously seals the devices, and the fabricated flexible devices have structural durability against bending. We have also shown that thermal lamination has an oriented growth effect, and the electrical characteristics of flexible organic field‐effect transistors did not degrade under a bending radius of 1 mm.magnified imageIn our thermal lamination method, organic thin film transistors are fabricated by a desktop laminator, like making plastic laminated cards.(© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Through experiments, we demonstrate accurate pulse shaping of femtosecond optical pulses in both amplitude and phase, prior to chirped pulse amplification. The nonlinear transfer function of the amplifier was compensated with feedback control referring to the amplified pulse shape measured by frequency resolved optical gating (FROG) or temporal analysis, by dispersing a pair of light e fields (TADPOLE). In FROG-referring control, the pulse shaper is adaptively controlled using a control index calculated from the two-dimensional FROG trace image, while in TADPOLE-referring control, the shaping phase-mask is corrected only a few times using the reconstructed spectrum phase of the output pulse. The performance and limitations of pre-shaping systems are discussed by comparing two pulse shaper devices, namely a liquid-crystal spatial light modulator and an acoustic optical phase dispersion filter, two pulse measurement techniques, and two feedback control schemes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.