The interaction of a laser-produced electron beam with an ultraintense laser pulse in free space is studied. We show that the optical pulse with a(0)=0.5 imparts momentum to the electron beam, causing it to deflect along the laser propagation direction. The observed 3-degree angular deflection is found to be independent of polarization and in good agreement with a theoretical model for the inte...

An undulator is proposed based on the plasma wakefields excited by a laser pulse in a plasma channel. Generation of the undulator fields is achieved by inducing centroid oscillations of the laser pulse in the channel. The period of such an undulator is proportional to the Rayleigh length of the laser pulse and can be submillimeter, while preserving high undulator strength. The electron trajecto...

In the paper, a 2 µm high energy fs fiber laser and amplification system is presented based on Tm doped fibers. The seed laser was designed to generate pulse train at 2024 nm at a repetition rate of 2.5 MHz. An AOM was used as a pulse picker to further lower the repetition rate down to 100 kHz. Two-stage fiber pre-amplifiers and a high energy large mode area (LMA) fiber amplifier were used to b...

The passively mode-locked laser1–5 has been a muchstudied device in recent years. Ultrashort-pulse generation in laser systems makes use of a variety of schemes, including figure-of-eight fiber laser design,1 fast saturable absorbers,4 additive-pulse mode locking,5 and nonlinear polarization rotation.6,7 The use of a semiconductor saturable absorber mirror8 with a relatively slow response time ...

We have been studying the pulse radiolysis using photo-cathode rf gun at Waseda Univ. Pulse radiolysis is one of the powerful methods to trace early chemical reactions by ionizing radiation. In pulse radiolysis, the probe light absorption, which produced by active species formed by electron beam of rf gun, is measured at each wavelength and made possible to trace reactions. Therefore, we have u...

A new, high-repetition-rate pulse-burst laser system for the MST Thomson scattering diagnostic has operated with 2 J pulses at repetition rates up to 75 kHz within a burst. The 1064 nm laser currently employs a q-switched, diode pumped Nd:YVO4 master oscillator, four Nd:YAG amplifier stages, and a Nd:glass amplifier, with plans for an additional Nd:glass amplifier. The laser can maintain 1.5–2 ...

a 2-d heat conduction model has been solved by using the adomian decomposition method topredict the transient temperature and heat flux distribution in a thick solid that is irradiated by a laser source.the laser source may operate in a continuous wave (cw) mode or repeated pulse (rp) mode and may havearbitrary, spatial and temporal profiles.a generalized solution containing five-terms approxim...

Full-waveform laser scanning extends the information content of “conventional” laser scanning by storing the temporal profile of both the emitted laser pulse and its echoes. This allows for calculating radiometric quantities in addition to the geometric data. This radiometric information needs to be calibrated in order to enable comparison among flight strips of the same laser scanner campaign ...

The improved laser-to-pedestal contrast ratio enabled by current high-power laser pulse cleaning techniques allows the fine features of the target survive before the main laser pulse arrives. We propose to introduce the nano-fabrication technologies into laser–plasma interaction to explore the novel effects of micro-structures. We found out that not only laser-driven particle sources but also t...

We have measured coincident ion pairs produced in the Coulomb explosion of H2 by 8-30 fs laser pulses at different laser intensities. We show how the Coulomb explosion of H2 can be experimentally controlled by tuning the appropriate pulse duration and laser intensity. For laser pulses less than 15 fs, we found that the rescattering-induced Coulomb explosion is dominated by first-return recollis...