Gilbert Damping for Various Ni80Fe20Thin Films Investigated Using All-Optical Pump–Probe Detection and Ferromagnetic Resonance

AbstractOptical pump-probe measurements were performed on planar slab waveguides containing silicon nanocrystals in an attempt to measure optical gain from photo-excited silicon nanocrystals. Two experiments were performed, one with a continuous-wave probe beam and a pulsed pump beam, giving a time resolution of approximately 25 ns, and the other with a pulsed pump and probe beam, giving a time resolution of approximately 10 ps. In both cases the intensity of the probe beam was found to be attenuated by the pump beam, with the attenuation increasing monotonically with increasing pump power. Time-resolved measurements using the first experimental arrangement showed that the probe signal recovered its initial intensity on a time scale of 45-70 μs, a value comparable to the exciton lifetime in Si nanocrystals. These data are shown to be consistent with an induced absorption process such as confined carrier absorption. No evidence for optical gain was observed.

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Эпитаксиальные напряжения в фотопроводящем слое InGaAs для THz-антенн

Письма в журнал технической физики ◽

10.21883/pjtf.2017.22.45260.16958 ◽

2017 ◽

Vol 43 (22) ◽

pp. 48

Author(s):

Д.И Хусяинов ◽

А.М. Буряков ◽

В.Р. Билык ◽

Е.Д. Мишина ◽

Д.С. Пономарев ◽

...

Keyword(s):

Optical Pump ◽

Pump Probe

Методами оптического зондирования при фемтосекундной лазерной накачке (optical pump-probe) и терагерцевой спектроскопии во временной области исследовано влияние эпитаксиальных напряжений на динамику неравновесных носителей заряда, а также спектр терагерцевого излучения в пленках InyGa1-yAs. Продемонстрировано снижение времени жизни неравновесных носителей заряда и увеличение ширины спектра терагерцевого излучения для пленки InyGa1-yAs с большим механическим напряжением. DOI: 10.21883/PJTF.2017.22.45260.16958

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Thermal Transport From Gold Nanorod to Solvent, an Investigation of Ligand Effects by Ultrafast Laser Spectroscopy

Volume 13: Nano-Manufacturing Technology; and Micro and Nano Systems, Parts A and B ◽

10.1115/imece2008-67266 ◽

2008 ◽

Author(s):

Joshua Alper ◽

Aaron Schmidt ◽

Kimberly Hamad-Schifferli

Keyword(s):

Heat Transfer ◽

Thermal Properties ◽

Gold Nanorods ◽

Thermal Transport ◽

Ultrafast Laser ◽

Ultrafast Laser Spectroscopy ◽

Optical Pump ◽

Thermal Interface ◽

Pump Probe ◽

Ligand Effects

To facilitate analysis of nanoscale heat transfer in nanoparticle systems the thermal properties of ligand layers must be understood. To this end, we use an optical pump-probe technique to study the thermal transport across ligands on gold nanorods and into the solvent. We find that varying properties of the ligand can have large impacts on the thermal decay of a nanorod after exposure to a laser pulse. By raising the concentration of free CTAB from 1 mM and 10 mM in solutions, the CTAB layer’s effective thermal interface conductance increases three fold. The transition occurs near the CTAB critical micelle concentration. Similar results are found for other ligand layers.

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