The dissociative ionization of ethanol C2H5OH in an intense laser field is investigated with a chirped pulse. From the sensitive dependence relative yields fragment ions on absolute values linear chirp rate, it shown that light-dressed potential-energy surface (LDPES) at singly charged stage governs nuclear dynamics, and wave packet flow into breaking either C–C C–O chemical bonds could be characterized by holding time thold during which LDPESs are maintained. It also understood term...

Two-body Coulomb explosion with the C–O bond breaking of methanol induced by intense laser pulses duration Δt=7 and 21fs is investigated coincidence momentum imaging method. When fs, angular distribution recoil vectors fragment ions for direct pathway, CH3OH2+→CH3++OH+, exhibits a peak deflected from polarization direction 30°–45°, corresponding migration CH2OH2+→CH2++H2O+, in which one hydrogen migrates carbon site to oxygen prior breaking, almost same profile. pulse stretched Δt=21fs,...

Abstract In terahertz (THz) wave generation by MgO:LiNbO 3 (LN) crystals, low extraction efficiency due to high refractive index (n = 4.93) in THz region is problematic. We propose and demonstrate an output coupler which consists of parallel plates with different indices couple out a the air ~ 1) more efficiently than without plates. Without any complicated processing on surface LN 1.8 times increase transmitted power was obtained.

Phycobilisomes are antenna protein complexes in cyanobacteria and red algae. In phycobilisomes, energy transfer is unidirectional with an extremely high quantum efficiency close to unity. We investigate intraprotein relaxation coherence of constituent chromoproteins allophycocyanin (APC) two kinds C-phycocyanin (CPC) phycobilisomes using two-dimensional electronic spectroscopy (2D-ES). These have similar adjacent pairs pigments $\alpha$84 $\beta$84, which excited delocalized exciton states....

Phycobilisomes are antenna protein complexes in cyanobacteria and red algae. In phycobilisomes, energy transfer is unidirectional with an extremely high quantum efficiency close to unity. We investigate intraprotein relaxation coherence of constituent chromoproteins allophycocyanin (APC) two kinds C-phycocyanin (CPC) phycobilisomes using two-dimensional electronic spectroscopy. These produced by Escherichia coli expression system have similar adjacent pairs pigments α84 β84, which excited...

Using a tandem time-of-flight mass spectrometer, benzene cations produced by the resonantly enhanced multiphoton ionization are separated and exposed to intense laser fields (∼2×1016 W/cm2) at λ∼790 395 nm with pulse duration of ∼50 fs. Comparing yields product ions those obtained from neutral molecules, dissociation dynamics in is investigated. At nm, formation parent dominant process irrespective initial charge states, i.e., major products when starting dications cation dications. On other...

Abstract We demonstrate the generation of sub-two-cycle intense laser pulses based on two-stage hollow-core fiber (HCF) compression in a compact setup (footprint 0.65 m × 2.85 m) using commercial Yb:KGW regenerative amplifier. Spectrally broadened with an output power 7.2 W from second HCF stage are compressed down to 6.6 fs (1.9 cycles at 1030 nm) pair chirp mirrors and wedges efficiency 86%, leading 6.2 W. A pulse-to-pulse energy stability 0.17% is measured for 10 min.

The ejection of hydrogen molecular ions from two-body Coulomb explosion processes methanol (CH3OH, CD3OH and CH3OD) in an intense laser field (800 nm, 60 fs, 0.2 PW cm−2) is investigated by a coincidence momentum imaging method. From the maps, ions, CH3OH2+→ Hm+ + CH(3−m)OH+(m = 2, 3), CD3OH2+→ Dm+ 3) CH3OD2+→ CH(3−m)OD+(m are identified. Based on results obtained with isotopically substituted methanol, isotope effect process discussed. Furthermore, H/D exchanged (HD+, HD2+ H2D+) identified,...

Valence molecular orbitals play a crucial role in chemical reactions. Here, we reveal that an intense laser field deforms inner valence orbital (10a') the ethanol molecule. We measure recoil-frame photoelectron angular distribution (RFPAD), which corresponds to orientation dependence of ionization probability orbital, using photoelectron-photoion coincidence momentum imaging with circularly polarized pulse. Ab initio simulations show deformation depends strongly on direction and measured...

The relative yield of the C-O bond breaking with respect to C-C in ethanol cation C2H5OH+ is maximized intense laser fields (10(13)-10(15) Wcm2) by open-loop and closed-loop optimization procedures. In optimization, a train pulses are synthesized so that temporal separation between first last becomes 800 fs, number width within systematically varied. When duration fs filled increasing or stretching all triple pulse train, significantly large. using self-learning algorithm, four dispersion...

We investigate coherent correlation between nonadiabatic rotational excitation and angle-dependent ionization of NO in intense laser fields the state-resolved manner. When neutral molecules are partly ionized (I(0) > 35 TW/cm(2)), a hole wave packet remaining is created because rate depending on alignment angle molecular axis with respect to polarization direction. Rotational state distributions experimentally observed, then characteristic feature that population at higher J levels increased...

The two dissociative ionization channels of ethanol (C2H5OH) induced by an intense near-infrared laser pulse (λ ∼ 783 nm), C2H5OH → CH2OH+ + CH3 e− and C2H5+ OH e−, are investigated using photoelectron-photoion coincidence method. It is shown that both the electronic ground state first electronically excited C2H5OH+ produced at moment photoelectron emission. From observed correlation between states prepared emission kinetic energy release fragment ions, it revealed in gains larger internal...

Femtosecond laser ablation dynamics of fused silica is examined via time-resolved reflectivity measurements. After optical breakdown was caused by irradiation a pump pulse with fluence Fpump = 3.3–14.9 J/cm2, the oscillated period 63 ± 2 ps for wavelength λ 795 nm. The reduced half 398 We ascribe oscillation to interference between probe pulses reflected from front and rear surfaces photo-excited molten layer. agrees closely model comprising layer which expands due formation voids, then...

We propose and experimentally demonstrate a method for characterizing vacuum ultraviolet (VUV) pulses based on time-resolved reflection spectroscopy of fused silica pumped by an intense laser pulse. Plasma mirror is used as ultrafast optical switch, which enables us to measure frequency-resolved gating (FROG) traces. The VUV temporal waveform can be retrieved from the measured FROG trace using principal component generalized projections algorithm with modification. profile plasma...

We demonstrate an optical parametric oscillator pumped at a repetition rate of 100 kHz by burst-mode Yb-doped fiber laser. Pulse energies 1.5 µJ were generated with five 4.8-µJ pump pulses. Pulse-to-pulse fluctuations could be suppressed even when only pulses used. The measured pulse length was 190 fs, which considerably shorter than the 350-fs length. operation is easy and powerful way to increase oscillators femtosecond

Ionization and subsequent electronic excitation occurring within the same laser pulse (400 nm, 96 fs, 1.3 ∼ 18 TW cm−2) are separately investigated by measuring in coincidence an electron a product ion produced from C2H5OH. It is revealed that nascent population electronically excited C2H5OH+ prepared ionization decreases as intensity increases, while enhanced through resonant transitions. mechanisms described based on electronic-state distributions of C2H5OH+.

We perform a beat-frequency-resolved analysis for two-dimensional electronic spectroscopy using high-speed and stable 2D spectrometer few-cycle visible laser pulses to disentangle the vibrational coherences in an artificial fluorescent protein. develop highly ultrashort light source that generates 5.3-fs with pulse energy of 4.7 µJ at repetition rate 10 kHz multi-plate compression filamentation gas cell. The above-5.3-fs together multichannel detector enable us measure series spectra, which...

We propose a strategy of isotope-selective ionization for binary mixture isotopologues homonuclear diatomic molecules, utilizing field-free alignment with train femtosecond laser pulses. Field-free can be achieved simultaneously two consisting atoms the same atomic mass number \ensuremath{\alpha} or \ensuremath{\beta} $({}^{\ensuremath{\alpha}}{X}_{2}\phantom{\rule{0.16em}{0ex}}\mathrm{and}\phantom{\rule{0.16em}{0ex}}{}^{\ensuremath{\beta}}{X}_{2})$, pulse their time interval...

Ultrafast photodissociation dynamics of OCS on the dissociative potential energy surface (PES) electronically excited 1Σ+ state was investigated by photofragment excitation (PHOFEX) spectroscopy and time-dependent wavepacket calculations. The high-resolution PHOFEX spectrum entire 1Σ+−1Σ+ transition (63 300−69 350 cm-1) in vacuum ultraviolet (vacuum UV) region measured under jet-cooled conditions using a tunable UV laser as an light source monitoring fragment S(1S) atom. Due to sufficient...