Control strategies for high-energy pulsed laser sources

Project focus

  • mathematical modelling and theoretic investigation of involved laser dynamics
  • development of adaptive model-based pulse shaping strategies
  • suppression of dynamic and stochastic instabilities by means of feedback control
  • explore the potential of systematic hardware/software codesign for pulsed laser sources


Short high-energy pulses of laser light have become a valuable and flexible tool with applications in basic research (i.e., in strong field physics, for pumping of optical parametric amplifiers and free electron lasers, or for coherent stimulation of atomic of molecular processes) as well as applications such as ablation-based material processing and laser-based eye surgery. The generation of particularly short pulses can be achieved by injecting seed pulses from a pulse source such as a mode-locked laser into resonator cavity with a pumped gain medium inside – a socalled master oscillator power amplifier (MOPA) concept. A more economic approach in case the required pulse durations allow it  is to self-seed the cavity from spontaneous emission – a traditional Q-switched laser.

Experimental pulsed laser system at the Institute of Photonics at TU Wien.

Many current and future applications of pulsed laser light require increasingly extreme operating parameters that entail specific issues depending on the chosen concept. For example, high repetition rates typically favoured in scanning or spectroscopic applications operate pumped resonator cavities close or within their dynamically unstable regime. This is particularly relevant if multiple amplification stages are economically or spatially unfeasible for the intended application. Additionally, the intrinsic stochastic fluctuations in self-seeded cavities often results in large energy fluctuations within the obtained pulse sequences that are highly detrimental for sensing applications. Another problem arises from the broad spectral bandwidth required for ultra-short pulsed operation, which leads to severely distorted and temporally broadened pulse shapes.

The timing requirements of modern pulse sources already largely relies on computerized control methods and the availability of programmable optical actuators such as acousto-optic modulators (AOMs) or spatial light modulators (SLMs). As a result, the application of advanced automatic control schemes can be used to mitigate or eliminate current limitations. Specifically, including the possibility of algorithmic solutions expands the range of strategies during the laser engineering process which in turn leads to more effective, more economic, and more flexible laser systems.

Selected publications

  • L. Tarra, A. Deutschmann-Olek, V. Stummer, T. Flöry, A. Baltuska, and A. Kugi, Stochastic nonlinear model of the dynamics of actively Q-switched lasers, Optics Express, vol. 30, iss. 18, p. 32411–32427, 2022.
    author = {Lukas Tarra and Andreas Deutschmann-Olek and Vinzenz Stummer and Tobias Fl\"{o}ry and Anrius Baltuska and Andreas Kugi},
    title = {Stochastic nonlinear model of the dynamics of actively Q-switched lasers},
    doi = {10.1364/OE.464508},
    number = {18},
    pages = {32411--32427},
    url = {},
    volume = {30},
    journal = {Optics Express},
    keywords = {Amplified spontaneous emission; Fiber lasers; Q switched lasers; Random lasers; Spontaneous emission; Stimulated Brillouin scattering},
    month = {Aug},
    publisher = {Optica Publishing Group},
    year = {2022},
  • A. Deutschmann, W. Kemmetmüller, and A. Kugi, On the global feedback stabilization of regenerative optical amplifiers, in Proceedings of the 21st IFAC World Congress, Berlin, Germany, 2020, p. 5447–5452.
    author = {A. Deutschmann and W. Kemmetmüller and A. Kugi},
    booktitle = {Proceedings of the 21st IFAC World Congress},
    title = {On the global feedback stabilization of regenerative optical amplifiers},
    doi = {10.1016/j.ifacol.2020.12.1547},
    note = {IFAC-PapersOnLine},
    number = {2},
    pages = {5447--5452},
    volume = {53},
    address = {Berlin, Germany},
    issn = {2405-8963},
    month = {06},
    year = {2020},
  • A. Deutschmann, T. Flöry, K. Schrom, V. Stummer, A. Baltuška, and A. Kugi, Bifurcation suppression in regenerative amplifiers by active feedback methods, Optics Express, vol. 28, iss. 2, pp. 1722-1737, 2020.
    [BibTex] [Download]
    author = {Deutschmann, A. and Fl\"ory, T. and Schrom, K. and Stummer, V. and Baltu\v{s}ka, A. and Kugi, A.},
    title = {Bifurcation suppression in regenerative amplifiers by active feedback methods},
    journal = {Optics Express},
    year = {2020},
    volume = {28},
    number = {2},
    pages = {1722-1737},
    doi = {10.1364/OE.380404},
  • A. Deutschmann, P. Malevich, A. Baltuska, and A. Kugi, Modeling and iterative pulse-shape control of optical chirped pulse amplifiers, Automatica, vol. 98, p. 150–158, 2018.
    [BibTex] [Download]
    author = {Deutschmann, A. and Malevich, P. and Baltuska, A. and Kugi, A.},
    title = {Modeling and iterative pulse-shape control of optical chirped pulse amplifiers},
    journal = {Automatica},
    year = {2018},
    volume = {98},
    pages = {150--158},
    issn = {0005-1098},
    doi = {10.1016/j.automatica.2018.09.002},


Ultrafast Laser Group, Photonics Institute at TU Wien