RP Photonics

Encyclopedia … combined with a great Buyer's Guide!


Pump–probe Measurements

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

Categories: optical metrology, methods

How to cite the article; suggest additional literature

Pump–probe measurements can be used to obtain information on ultrafast phenomena. The general principle is the following. A sample (e.g. a SESAM) is hit by some pump pulse, which generates some kind of excitation (or other modification) in the sample. After an adjustable time delay (controlled with an optical delay line), a probe pulse hits the sample, and its transmission or reflection is measured. By monitoring the probe signal as a function of the time delay, it is possible to obtain information on the decay of the generated excitation, or on other processes initiated by the pump pulses. The probe signal is typically averaged over many pulses, and a fast photodetector is not required. The temporal resolution is fundamentally limited only by the pulse duration of pump and probe pulses.

reflectivity change in a SESAM, caused by a short pulse
Figure 1: Reflectivity change in a semiconductor saturable absorber, hit by a short pulse at t = 0.

The wavelengths of pump and probe beam do not need to be identical. A so-called two-color pump–probe measurement, based on two synchronized sources of short pulses (e.g. a laser and an optical parametric oscillator, or two parametric oscillators pumped with the same laser) has additional capabilities in ultrafast laser spectroscopy. It is vital in such cases to ensure tight synchronization of the different laser sources with a very low relative timing jitter, as the jitter could otherwise spoil the attainable temporal resolution.

Pump–probe measurements can be used, for example, to monitor the recovery of a saturable absorber after its excitation, the speed of diffusion of photoexcited carriers, or the melting of a sample after being hit by an intense pulse.

Pump–probe methods are also used in various methods of time-resolved spectroscopy.


The RP Photonics Buyer's Guide contains 6 suppliers for pump--probe measurement equipment. Among them:

See also: time-resolved spectroscopy, ultrafast optics, saturable absorbers, semiconductor saturable absorber mirrors, optical sampling, synchronization of lasers, laser spectroscopy
and other articles in the categories optical metrology, methods

How do you rate this article?

Click here to send us your feedback!

Your general impression: don't know poor satisfactory good excellent
Technical quality: don't know poor satisfactory good excellent
Usefulness: don't know poor satisfactory good excellent
Readability: don't know poor satisfactory good excellent

Found any errors? Suggestions for improvements? Do you know a better web page on this topic?

Spam protection: (enter the value of 5 + 8 in this field!)

If you want a response, you may leave your e-mail address in the comments field, or directly send an e-mail.

If you enter any personal data, this implies that you agree with storing it; we will use it only for the purpose of improving our website and possibly giving you a response; see also our declaration of data privacy.

If you like our website, you may also want to get our newsletters!

If you like this article, share it with your friends and colleagues, e.g. via social media: