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Optically induced magnetization, whose relaxation time is of the order of a hundred picoseconds, and coherent oscillations of magnons in terahertz region were observed in an antiferromagnet NiO by polarization spectroscopy with the pump-probe technique.
For controlling non-resonant molecular fragmentation process, simultaneous effect of chirp and polarization of a femtosecond pulse is mutually independent. For multiphoton fluorescence microscopy and optical tweezers with high-repetition-rate lasers, inter-pulse separation and polarization is important.
Novel method for relative phase measurement between optical longitudinal modes has been proposed and named as “dual heterodyne mixing method”. It was applied for 12.5GBps BPSK signal sensing by 200MHz low-speed receiver.
We show through numerical simulations that optical pulses in silicon waveguides can undergo significant self-induced changes in their polarization state. These changes are mediated mostly by free-carrier dispersion and depend on waveguide dimensions.
Using electron-beam-induced deposition and focused-ion-beam milling, we have fabricated and demonstrated a nanofocusing optical transformer with a 3-dimensionally tapered tip. At the tip, the light is confined to 13-by-80-nm area with intensity enhancement exceeding 1500.
We generate 800-nm, sub-7-fs pulses from a degenerate Optical Parametric Amplifier pumped by the second harmonic of a Ti:sapphire system and seeded by supercontinuum generated by a near IR OPA pumped by the same source.
The effect of optical feedback is investigated for a quantum-dash-based passive mode-locked laser. We observe a drastic reduction of the radio frequency spectrum linewidth even beyond the onset of coherence collapse.
We present an ultra-broadband optical parametric amplification system based on aperiodically poled Mg:LiNbO3 providing 800 nm bandwidth around 3.4 μm in a 7.4-mm long medium. It delivers 75 fs pulses with 1.5 μJ pulse energy.
Few-fermion dynamics in a single CdSe/ZnSe quantum dot after resonant excitation is investigated via femtosecond transmission spectroscopy. Optimized coupling via dielectric microcavities and plasmonic nanoantennas is discussed leading towards ultrafast nonlinear optics with single photons.
Photoexcitation of carbon nanotubes generates excitons which decay by exciton-exciton annihilation at sufficient density. We examine this decay under conditions of one, few and many excitons per nanotube. A classic 1D reaction-diffusion behaviour is observed, with decay limited by diffusion for t>3ps and by reaction for t<;3ps. At high densities the exciton population saturates, and by analysis...
We demonstrate the use of optically generated geometric phases to modify the phase of one of the spin states of an electron confined in an InAs quantum dot, effectively executing a spin phase gate.
A fiber-based compact source of mid-infrared ultrafast laser pulses is presented. A polarization-maintaining fiber amplifier provides the pump pulses, while the signal pulses are derived from the same source by soliton self-frequency shifting in the same fiber. Noise and jitter of the fiber pulses are characterized.
By exciting with sub-10-fs 1.6-µm pulses the quasi-one-dimensional Mott insulator ET-F2TCNQ, we observe prompt collapse of the Mott gap modulated by 24-THz oscillations of the gap, which are assigned to quantum interference between holon-doublon excitations.
We generate Sommerfeld-Brillouin precursors from a square-modulated laser pulse through a cold atomic ensemble with electromagnetically induced transparency. At a high optical depth, the precursor forerunner is clearly separated from the delayed main pulse.
We present the progress made in developing 10PW OPCPA facility for the Vulcan laser to produce pulses with focused intensities >1023 Wcm−2. This power level will be delivered by generating pulses with >300J in 30fs. These pulses will be delivered to two target areas: in one target area they will be combined with the existing Vulcan Petawatt beamline and a new target area will be created for...
We report the continuous mode-locked operation of a picosecond, singly-resonant, synchronously-pumped optical parametric oscillator (SPOPO) based on ZGP. The ZGP SPOPO emits in the 4-6 μm range with signal power higher than 800 mW.
Spatiotemporal aberrations from megahertz-repetition-rate noncollinear optical parametric amplifiers are characterized using spatially resolved spectral interferometry. Pulse-front tilt is eliminated by optimizing the signal's angular gain spectrum, increasing the intensity at focus.
A novel scheme using single phase modulator for simultaneous generating and decoding of time domain spectral phase encoded signal and DPSK data modulation is proposed and experimentally demonstrated for five 16-chip, 40GHz/chip optical code patterns.
Using a two stage, white-light seeded, collinear, femtosecond optical parametric amplifier based on BIBO crystals, sub-30-fs signal pulses tunable across the whole spectral range of 1150–1600 nm with energies exceeding 80-µJ are generated.
We have successfully realized an optical frequency tunable Cs atomic clock with a mode-hop-free fiber laser. The optical frequency of the 9.1926 GHz clock was continuously tuned over 1 GHz without changing the clock frequency.
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