What is the pump-probe technique?

What is the pump-probe technique?

The pump-probe technique enables us to measure ultrafast phenomena inside matter such as the movement of atoms or electron excitations, thanks to very short laser pulses. In order to do this, a very short and intense laser pulse, the “pump”, is sent on an object to excite it.

What is a pump-probe experiment?

Pump-probe experiment. A pump-probe experiment utilizes two light beams, a pump beam and a probe beam, that interact with a sample material. The pulses from the pump beam interact with the sample. The probe beam monitors any changes (such as sample transmission) that may have taken place due to the pump beam.

What is time resolved anisotropy?

Fluorescence anisotropy measures the depolarisation of the fluorescence emission. The main reasons for depolarisation include the energy transfer to another molecule with a different orientation or molecular rotation caused by Brownian motion.

What is probe pulse?

Definition: techniques for investigating ultrafast phenomena, where a pump pulse excites a sample and a probe pulse is used for probing the sample after an adjustable delay time. German: Pump-Probe-Messungen.

What is pump pulse?

Pulsation is the result of uncontrolled pressure waves caused by a change in flow. Media in a pump has a mass and there are required acceleration forces needed to move it. Once in motion, media will remain so as the force is sufficient and friction is minimal.

What is time resolved photoluminescence?

Time-Resolved Photoluminescence (TRPL) is the tool of choice for studying fast electronic deactivation processes that result in the emission of photons, a process called fluorescence. TCSPC works by measuring the time between sample excitation by a laser pulse and the arrival of the emitted photon at the detector.

How does pump probe spectroscopy work?

In this technique, an ultrashort laser pulse is split into two portions; a stronger beam (pump) is used to excite the sample, generating a non-equilibrium state, and a weaker beam (probe) is used to monitor the pump-induced changes in the optical constants (such as reflectivity or transmission) of the sample.

How does femtosecond spectroscopy work?

During the process, known as femtosecond spectroscopy, molecules were mixed together in a vacuum tube in which an ultrafast laser beamed two pulses. The characteristic spectra, or light patterns, from the molecules were then studied to determine the structural changes of the molecules.

What is the time resolution of the pump probe spectroscopy?

The time resolution of the pump probe spectroscopy has a direct relationship with the pulse duration used in the experiment. Femtosecond laser pulse can make the time resolution of this technique goes to femtosecond scale. This enables researchers to know many quite fast dynamic processes happened when the pump pulse passes through the sample.

What is 2PPE (time-resolved photoemission spectroscopy)?

Time-resolved photoemission spectroscopy and two-photon photoelectron spectroscopy (2PPE) are important extensions to photoemission spectroscopy. These methods employ a pump-probe setup. In most cases the pump and probe are both generated by a pulsed laser and in the UV region.

What is timetime resolved absorption spectroscopy?

Time resolved absorption spectroscopy relies on our ability to resolve two physical actions in real time. The shorter the detection time, the better the resolution. This leads to the idea that femto-second laser based spectroscopy offers better resolution than nano-second laser based spectroscopy.

What is the difference between a pump pulse and probe beam?

The pump pulse is typically in the UV region and is often generated by a high-powered Nd:YAG laser, whereas the probe beam is in the infrared region.