Temporal characterisation of ultrashort laser pulses from a terawatt laser system
(2025) In Lund reports on atomic physics (LRAP) PHYM03 20251Atomic Physics
Department of Physics
- Abstract
- The advent of few-femtosecond laser pulses has revolutionized our ability to probe ultrafast phenomena in atoms, molecules, and solids, yet reliable temporal characterization in terawatt-scale laser systems remains challenging due to their complexity. Measurements along the path of the light from the source to end of the beamlines have to be undertaken not just for temporal characterisation of the pulses but for the optimisation of the beam at each individual position. For the temporal characterisation, dispersion scan was used in order to obtain the fundamental spectrum, the spectral phase and the temporal pulse shape at each measurement point for pulse reshaping by using an acousto-optic programmable dispersive filter known as the... (More)
- The advent of few-femtosecond laser pulses has revolutionized our ability to probe ultrafast phenomena in atoms, molecules, and solids, yet reliable temporal characterization in terawatt-scale laser systems remains challenging due to their complexity. Measurements along the path of the light from the source to end of the beamlines have to be undertaken not just for temporal characterisation of the pulses but for the optimisation of the beam at each individual position. For the temporal characterisation, dispersion scan was used in order to obtain the fundamental spectrum, the spectral phase and the temporal pulse shape at each measurement point for pulse reshaping by using an acousto-optic programmable dispersive filter known as the Dazzler. A state-of-the-art d-scan retrieval algorithm was written in the scope of the master project in order to retrieve the spectral phases used for pulse reshaping. Ultimately, the efficiency of high-order harmonic generation will be increased due to the optimised intense laser beam. (Less)
- Popular Abstract
- Imagine trying to take a photograph of a hummingbird’s wings as they beat thousands of times per second—it’s practically impossible with an ordinary camera. Now replace that hummingbird with a light pulse lasting just a few quadrillionths of a second (a few femtoseconds), and you begin to appreciate the challenge of “seeing” and precisely controlling such ultrafast bursts of light - especially when they pack the power of a small power plant (terawatts - trillions of watts) into a beam no thicker than a human hair.
In this work, we have developed and demonstrated a compact, all-in-one method to both measure and shape these lightning-fast, terawatt-power laser pulses in real time. Using a clever technique called dispersion scan (or... (More) - Imagine trying to take a photograph of a hummingbird’s wings as they beat thousands of times per second—it’s practically impossible with an ordinary camera. Now replace that hummingbird with a light pulse lasting just a few quadrillionths of a second (a few femtoseconds), and you begin to appreciate the challenge of “seeing” and precisely controlling such ultrafast bursts of light - especially when they pack the power of a small power plant (terawatts - trillions of watts) into a beam no thicker than a human hair.
In this work, we have developed and demonstrated a compact, all-in-one method to both measure and shape these lightning-fast, terawatt-power laser pulses in real time. Using a clever technique called dispersion scan (or “d-scan”), we spread the pulses in time and measure how they are changed as they go through different thicknesses of glass. Feeding this information into a programmable dispersive filter (the Dazzler), we could then correct tiny distortions and compress the pulses back down to nearly their shortest possible duration — less than ten femtoseconds!
Why does this matter? Pulses at terawatt power are the essence of ultrafast science, but their extreme intensity can introduce subtle effects which distort and elongate the pulses. When these perfectly tuned, high-power light pulses are focused into a gas, they can generate new light at much shorter wavelengths, producing extreme ultraviolet (XUV) flashes lasting a few attoseconds (three orders of magnitude shorter than femtoseconds). These attosecond flashes are the fastest “camera flashes” ever created, capable of filming electrons as they circulate around atoms. Better control over the driving laser pulse means brighter, more stable XUV bursts, enabling us to monitor electronic dynamics in real time more clearly.
Our approach is compact, robust, and is based on closed-loop feedback, making it ideal for next-generation laser laboratories. By bringing precise, hands-off control to the world’s shortest and most powerful light pulses, we’re one step closer to uncovering nature’s fastest secrets. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9209465
- author
- Nagy, Péter Zoltán LU
- supervisor
-
- Per Johnsson LU
- Miguel Canhota LU
- Venus Poulain LU
- organization
- alternative title
- Temporal karakterisering av ultrasnabba laserpulser från ett terawattlasersystem
- course
- PHYM03 20251
- year
- 2025
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- ultrashort pulses, femtosecond pulses, temporal characterisation, dispersion scan (d-scan), retrieval algorithm, ptychography, high-order harmonics
- publication/series
- Lund reports on atomic physics (LRAP)
- report number
- LRAP 614
- language
- English
- id
- 9209465
- date added to LUP
- 2025-08-07 08:14:54
- date last changed
- 2025-08-07 08:14:54
@misc{9209465,
abstract = {{The advent of few-femtosecond laser pulses has revolutionized our ability to probe ultrafast phenomena in atoms, molecules, and solids, yet reliable temporal characterization in terawatt-scale laser systems remains challenging due to their complexity. Measurements along the path of the light from the source to end of the beamlines have to be undertaken not just for temporal characterisation of the pulses but for the optimisation of the beam at each individual position. For the temporal characterisation, dispersion scan was used in order to obtain the fundamental spectrum, the spectral phase and the temporal pulse shape at each measurement point for pulse reshaping by using an acousto-optic programmable dispersive filter known as the Dazzler. A state-of-the-art d-scan retrieval algorithm was written in the scope of the master project in order to retrieve the spectral phases used for pulse reshaping. Ultimately, the efficiency of high-order harmonic generation will be increased due to the optimised intense laser beam.}},
author = {{Nagy, Péter Zoltán}},
language = {{eng}},
note = {{Student Paper}},
series = {{Lund reports on atomic physics (LRAP)}},
title = {{Temporal characterisation of ultrashort laser pulses from a terawatt laser system}},
year = {{2025}},
}