相关论文: Ultrafast laser-triggered emission from hafnium ca…
The influence of laser frequency on laser-driven ion acceleration is investigated by means of two-dimensional particle-in-cell simulations. When ultrashort intense laser pulse at higher harmonic frequency irradiates a thin solid foil, the…
In this work, dynamics of multi-charged ions emitted from an aluminum plasma produced by Q switched Nd: Yag laser is studied using time of flight (TOF) measurements from Langmuir Probe (LP) and spectroscopy (STOF) under Ar ambient of 0.02…
We analyse the effects of applying an electric field on the critical temperature, Ts, at which superionicity appears in archetypal fast ion conductor CaF2 by means of molecular dynamics simulations. We find that the onset of superionicity…
Ultrafast laser material processing has received significant attention due to a growing need for the fabrication of miniaturized devices at micro- and nanoscales. The traditional phenomenological laws, such as Fourier's law of heat…
Using transient absorption (TA) microscopy as a hot electron thermometer we show disorder-assisted acoustic-phonon supercollisions (SCs) best describes the rate-limiting relaxation step in graphene over a wide range of lattice temperatures…
The famous Two-Temperature Model (TTM) used extensively in the investigations of energy relaxation in photo-excited systems originated in the seminal work of M. I. Kaganov, I. M. Lifshitz, and L. V. Tanatarov (KLT) in 1957. The idea that…
Terahertz (THz) radiation can be generated by ultrafast photo-excitation of carriers in a semiconductor partly masked by a gold surface. A simulation of the effect taking into account the diffusion of carriers and the electric field shows…
We demonstrate a nanotip electron source based on a graded index multimode silica optical fiber, tapered at one end to a radius of curvature r ~ 50 nm and coated with a thin film of gold. We report observation of laser-induced electron…
We report the first experimental observations of two-photon emission from semiconductors, to the best of our knowledge, and develop a corresponding theory for the room-temperature process. Spontaneous two-photon emission is demonstrated in…
Ultrafast dynamics of graphite is investigated by time-resolved photoemission spectroscopy. We observe spectral features of direct photoexcitations, non-thermal electron distributions, and recovery dynamics occurring with two time scales…
We report THz-pump / mid-infrared probe near-field studies on Si-doped GaAs-InGaAs core-shell nanowires utilizing THz radiation from the free-electron laser FELBE. Upon THz excitation of free carriers, we observe a red shift of the plasma…
The thermal lensing effects in the lasing crystal appear to be dominant when the pump laser focused on the lasing crystal which causes the local heating effect. The spatial refractive index variations observed if the crystal has non-uniform…
We measure the temperature distribution in a biased single-layer graphene transistor using Raman scattering microscopy of the 2D-phonon band. Peak operating temperatures of 1050 K are reached in the middle of the graphene sheet at 210 KW…
We analyse the influence of heat generation by non radiative transitions in high power 1.55$\mu$m double cladding Erbium-Ytterbium fiber laser. At strong pumping rates, 1$\mu$m lasing can start due to parasitic reflections. We present a…
Direct measurements of photoexcited carrier dynamics in nickel are made using few-femtosecond extreme ultraviolet (XUV) transient absorption spectroscopy at the nickel M$_{2,3}$ edge. It is observed that the core-level absorption lineshape…
In this paper we study photon emission in the interaction of the laser beam with an under-dense target and the attached reflecting plasma mirror. Photons are emitted due to the inverse Compton scattering when accelerated electrons interact…
We built a frequency-doubled laser for 87Rb laser cooling, from a Telecom fiber laser. Thanks to intense technological development, telecom fiber lasers exhibit outstanding properties regarding relative intensity noise and modulation…
Observations of polariton condensation in semiconductor microcavities suggest that polaritons can be exploited as a novel type of laser with low input-power requirements. The low-excitation regime is approximately equivalent to thermal…
Ultrafast optical pump-probe spectroscopy measurement on monolayer graphene observes significant optical nonlinearities. We show that strongly photoexcited graphene monolayers with 35 fs pulses quasi-instantaneously build up a broadband,…
Recent theoretical predictions hint at an implementation of a superradiant laser based on narrow optical clock transitions by using a filtered thermal beam at high density. Corresponding numerical studies give encouraging results but the…