Femtosecond Pump-probe
Femtosecond Pump-probe - Related Videos
09:49
An Experimental Protocol for Femtosecond NIR/UV - XUV Pump-Probe Experiments with Free-Electron Lasers
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Cited by 13 •
2018
This protocol describes the key steps for performing and analyzing pump-probe experiments combining a femtosecond optical laser with a free-electron laser in order to study ultrafast photochemical reactions in gas-phase molecules.
13:02
Fabrication of 1-D Photonic Crystal Cavity on a Nanofiber Using Femtosecond Laser-induced Ablation
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Cited by 3 •
2017
We present a protocol for fabricating 1-D photonic crystal cavities on subwavelength diameter silica fibers (optical nanofibers) using femtosecond laser-induced ablation.
15:58
Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing
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Cited by 3 •
2013
The technique of femtosecond four-wave mixing is described, including spectrally-resolved and time-resolved configurations. We illustrate the utility of this technique for the investigation of crucial physical properties in the III-V diluted magnetic semiconductors, afforded by its nonlinearity and high temporal resolution.
01:30
ATP Driven Pumps III: V-type Pumps
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2023
V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient. The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
01:34
ATP Driven Pumps II: P-type Pumps
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2023
The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V. A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
FAQs
The pump and probe pulses divide the experiment into initiation and observation. The pump deposits light to start a photochemical process, while the delayed probe interrogates the system at a selected moment. Changing that delay lets measurements follow the same reaction at successive stages, linking a transient signal to its position in the evolving molecular response.
Transient absorption, emission, or reflectivity provides different observable signatures of the evolving state. In chemical studies, their time-dependent behavior can identify excited-state lifetimes, electron transfer, energy transfer, or bond rearrangements. This makes the method useful for distinguishing short-lived intermediate behavior from the later state observed after the initial excitation.
A single delay captures only one moment in the molecular response. Scanning the interval between the pump and probe produces a sequence of time-resolved observations, allowing the experiment to reconstruct how electronic and structural properties change after excitation. The resulting timeline connects the onset of a photochemical event with its subsequent evolution and chemical consequences.
Steady-state measurements generally describe an overall or persistent optical response, whereas femtosecond pump-probe follows changes immediately after light absorption. Its time resolution exposes excited-state lifetimes, transfer events, and bond rearrangements that can be hidden when signals from different stages are combined. This distinction helps relate transient molecular behavior to photochemical reactivity.
A typical workflow uses a pump pulse to initiate the molecular process, introduces a controlled time delay, and applies a probe pulse to sample transient absorption, emission, or reflectivity. The delay is then scanned, and the resulting measurements are assembled into a time-dependent picture. That reconstruction reveals how the system’s electronic and structural state develops after excitation.
The technique is valuable when researchers need to connect molecular structure with light-driven reactivity. It can examine excited-state lifetimes, electron or energy transfer, and bond rearrangements in systems relevant to photocatalysts, solar-energy materials, and light-responsive molecular systems. These measurements support understanding and design by showing which transient processes accompany useful photochemical behavior.