Ultrafast Lasers

Since they generate very short light-matter interaction times and large radiation intensities, lasers with ultrashort pulses (USP lasers) have great advantages for applications with special requirements. They enable high-precision material processing – even with difficult-to-process materials – with negligible heat input into the processed workpieces.

At Fraunhofer ILT, USP beam sources are being developed that provide application-specific optimized wavelengths, powers or pulse frequencies. In the area of power scaling of USP laser systems, Fraunhofer ILT has already achieved several record levels. Currently, it is focusing its research and development on laser amplifiers with wavelengths in the near infrared, pulse durations of 10 fs to 1 ps, output powers of 100 mW to 5 kW and pulse energies in the range 1 nJ to 100 mJ with diffraction-limited beam quality. The institute uses and continues to develop INNOSLAB, rod and disk laser amplifiers as well as sources for coherent VUV and EUV radiation. A promising future field of application for high-power ultrashort pulse lasers is the laser cutting and removal of difficult-to-machine materials, such as CFRP, with high speeds and high precision. For this purpose, technologies for pulse reduction will be developed further and a power scaling in the multi-kilowatt range targeted.

The services offered by Fraunhofer ILT include feasibility studies, simulations, experimental investigations, the automation of lasers, the development of industry-oriented prototypes, and consulting.

fs-Oscillators

• KLM
• Cr:Colquiriite
• Yb:YAG / KGW / Lu2O3
• Modeling Kerr-effect, pumping radiation, gain saturation

Broad Band Amplifier

• Diode pumped up to 1kW average output power
• Yb:YAG / KGW / Lu2O3
• Cr:Colquiriite
• 3D modeling of 3-level systems and beam propagation

Dispersion Measurement

• Group delay - dispersion measurement of optics
• Wavelength range l = 250 - 1700 nm
• Resolution Dl = 1 nm / DD2 = 3fs2

Generation of Radiation

• Incoherent X-rays
• Coherent EUV / XUV
• Electrons

Wissenberg, S. H. , Weitenberg, J. , Moreno, J., Hartung, H. , Möslein, M. , Burkhardt, Th., Teschler, T., Schmid, F., Udem, Th. , Hoffmann, H.-D., Thirolf, P. G., Hänsch, Th. W., Ozawa, A., Haefner, C. L.:
Noncollinear enhancement resonator with intrinsic pulse synchronization and alignment employing wedge mirrors.
Physics Review Research 7(2), 023071-, (2025)
https://doi.org/10.1103/PhysRevResearch.7.023071 (Open Access)

Eisenbach, L, Wang, Z., Schulte, J., Heuermann, T., Russbüldt, P., Meyer, R., Gierschke, P., Lenski, M., Sugiura, M., Tamura, K., Limpert, J., Haefner, C.:
Highly efficient, high average power nonlinear compression of mJ pulses at 2 µm wavelength below 20 fs in a gas-filled multi-pass cell.
Journal of Physics: Photonics 6(3), 035015, (8 S,) (2024)
https://doi.org/10.1088/2515-7647/ad4cc4 (Open Access)

Schmid, F., Moreno, J., Weitenberg, J., Rußbüldt, P., Hänsch, Th. W., Udem, Th., Ozawa, A.:
An ultra-stable high-power optical frequency comb.
APL Photonics 9, 26105- (2024)
https://doi.org/10.1063/5.0165805 (Open Access)

Thirolf, P., Krämer, S., Weitenberg, J.:
Thorium-229-Kernuhren für ultragenaue Zeitmessung und Quantensensorik - Mehr als ein hochgenauer Zeitmesser.
Physik in unserer Zeit 55(3), Online First (2024)
https://doi.org/10.1002/piuz.202301696  (Open Access)

Haasler, D., Surrey, R., Bremer, P.:
Ablation of technical ceramics via cw-laser radiation and comparison with an ultrashort-pulsed laser ablation process.
24th International Symposium on Laser Precision Microfabrication, 13.-15.6.2023, Hirosaki, Japan.
Proceedings of LPM2023, C000176, (8 S.), (2023)

Lanfermann, A., Barthels, T., Nießen, M., Abels, P., Klass, G., Riester, C., Pham, T.Q., Steffens, O.,
INNOVATIVE FILTER MODULE TO SEPARATE MICROPLASTICS FROM WASTEWATER – SIMCONDRILL.
FILTECH 2022, 8-10. March 8-10, 2022, Cologne, Germany. FILTECH : March 8-10, 2022, Cologne, Germany:the filtration event, 10 S., (2022)

Barthels,T., Nießen, M., Abels, P., Klass, G., Riester, C., Pham, T.Q., Steffens, O.,
Innovative Filtermodule für die Abscheidung von Mikroplastik aus Abwasser.
GWF: Wasser, Abwasser 163, 51-54 (2022)

Lanfermann, A, Barthels, T., Nießen, M., Abels, P., Klass, G., Riester, C., Pham, T.Q., Steffens, O.:
Innovative Filtermodule für die Abscheidung von Mikroplastik aus Abwasser.
F&S Filtrieren &Separieren F&S 01 | 2022
28-30 (2022)

Russbueldt, P., Weitenberg, J., Schulte, J., Meyer, R., Meinhardt, C., Hoffmann, H.-D., Poprawe, R.:
Scalable 30 fs laser source with 530 W average power.
OPTICS LETTERS 44, 5222-5225 (2019)
https://doi.org/10.1364/OL.44.005222

Schulte, J., Sartorius, T., Weitenberg, J., Vernaleken, A., Russbueldt, P.:
375-W 37.5- μJ less than 170 fs laser system utilizing nonlinear pulse compression in fused silica.
Solid State Lasers XXVI: Technology and Devices, San Francisco, California, United States 27 January - 1 February 2017. Proc. of SPIE Vol. 10082, 1008217- (2017)
https://doi.org/10.1117/12.2250920

Weitenberg, J., Vernaleken, A., Schulte, J., Ozawa, A., Sartorius, T., Pervak, V., Hoffmann, H.-D., Udem, T., Russbüldt, P., Hänsch, T. W.:
Multi-pass-cell-based nonlinear pulse compression to 115 fs at 7.5 μJ pulse energy and 300 W average power.
OPTICS EXPRESS 25, 20502- (2017)
https://doi.org/10.1364/OE.25.020502 (Open Access)

Carstens,H., Högner, M., Saule, T., Holzberger, S., Lilienfein, N., Guggenmos, A., Jocher, C., Eidam, T., Esser, D., Tosa, V. Pervak, V., Limpert, J., Tünnermann A., Kleineberg, U., Krausz, F., Pupeza, I.:
Cavity-enhanced high-harmonic generation at 250 MHz.
High Intensity Lasers and High Field Phenomena 2016. Long Beach, California, United States, 20–22 March 2016. Paper HM6B.6, 1-2 (2016)
https://doi.org/10.1364/HILAS.2016.HM6B.6

Schulte, J., Sartorius, T., Weitenberg, J., Vernaleken, A., Russbueldt, P.:
Nonlinear pulse compression in a multi-pass cell
Opt. Lett. 41 (19), 4511-4514 (2016)
https://doi.org/10.1364/OL.41.004511

Wueppen, J., Strotkamp, M., Hoffmann, D., Russbueldt, P., Mans, T., Fritzler, S., Schippel, S.:
Laser-triggered electron source for x-ray applications
In: Ultrashort Pulse Laser Technology: Laser Sources and Applications
Eds.: Nolte, S.; Schrempel, F.; Dausinger, F. Cham [u.a.]: Springer (2016), 337-349
https://doi.org/10.1007/978-3-319-17659-8_15

Esser, D., Staasmeyer, J.-H., Weitenberg, J., Rußbüldt, T., Sartorius, T., Hoffmann, H.-D.:
Fused-silica mirror substrates with laser-microstructured openings with reduced chipping
2015 European Conference on Lasers and Electro-Optics - European Quantum Electronics Conference, 21-25 June 2015 in Munich. CE_10_3. (2015)

Finger, J., Kalupka C., Reininghaus, M.:
High power ultra-short pulse laser ablation of IN718 using high repetition rates
J. Materials Processing Technol. 226 (Dec.), 221-227 (2015)
https://doi.org/10.1016/j.jmatprotec.2015.07.014

Fornaroli, C., Holtkamp, J., Gillner, A.:
Dicing of thin silicon wafers with ultra-short pulsed lasers in the range from 200 fs up to 10 ps
J. Laser Micro/Nanoeng. 10 (2), 229-233 (2015)
https://doi.org/10.2961/jlmn.2015.02.0022

Russbueldt, P., Hoffmann, D., Höfer, M., Löhring, J., Luttmann, J., Meissner, A., Weitenberg, J., Traub, M., Sartorius, T., Esser, D., Wester, R., Loosen, P., Poprawe R.:
Innoslab amplifiers
IEEE Journal of Selected Topics in Quantum Electronics 21,
3100117-3100117 (2015)
https://doi.org/10.1109/JSTQE.2014.2333234

Weitenberg, J., Rußbüldt, P.,  Pupeza, I., Udem, Th., Hoffmann, H.-D.,  Poprawe, R.:
Geometrical on-axis access to high-finesse resonators by quasi-imaging: a theoretical description
Journal of Optics A-Pure and Applied Optics 17(2), 1-17 (2015)
https://doi.org/10.1088/2040-8978/17/2/025609 (Open Access)

Bensmann, S., Gaußmann, F., Lewin, M., Wüppen, J., Nyga, S., Janzen, C., Jungbluth, B., Taubner, T.:
Near-field imaging and spectroscopy of locally strained GaN using an IR broadband laser
Opt. Expr. 22 (19), 22369-22381 (2014)
https://doi.org/10.1364/OE.22.022369 (Open Access)

Carstens, H., Lilienfein, N., Holzberger, S.: Jocher, C., Eidam, T., Limpert, J., Tünnermann, A., Weitenberg, J., Malgamdi, A., Alahmed, Z., Azzeer, A., Apolonski, A., Fill, E., Pupeza, I., Krausz, F.:
Thermal limitations for power scaling of femtosecond enhancement cavities 
High Intensity Lasers and High Field Phenomena (HILAS) 2014. Paper: HTu1C.6 (3 S.) (2014)
https://doi.org/10.1364/HILAS.2014.HTu1C.6

Carstens, H., Lilienfein, N., Holzberger, S., Jocher, C., Eidam, T., Limpert, J., Tünnermann, A., Weitenberg, J., Yost, D. C., Alghamdi, A., Alahmed, Z., Azzeer, A., Apolonski, A., Fill, E., Krausz, F., Pupeza, I.:
Megawatt-scale average-power ultrashort pulses in an enhancement cavity
Opt. Lett. 39 (9), 2595-2598 (2014)
https://doi.org/10.1364/ol.39.002595 (Open Access)

Gronloh, B., Russbueldt, P., Jungbluth, B., Hoffmann, H.-D.:
Ultrafast green laser exceeding 400 W of average power
SPIE Photonics Europe, 2014, Brussels, Belgium.
Proceedings Volume 9135, Laser Sources and Applications II; 91350C (2014)
http://dx.doi.org/10.1117/12.2051510

Holzberger, S., Högner, M., Weitenberg, J., Esser, D., Eidam, T., Limpert, J., Tünnermann, A., Fill, E., Krausz, F., Yakovlev, V. S., Pupeza, I.:
Power-scalable and efficient geometric XUV output coupling for cavity-enhanced high harmonic generation
CLEO 2104 - Laser Science to Photonic Applications. 08 Jun 2014 - 13 Jun 2014, San Jose, California, USA. 2 S. (2014)
https://doi.org/10.1364/CLEO_QELS.2014.FTu2D.3

Petraviciute-Lötscher, L., Schneider, W., Rußbüldt, P., Gronloh, B., Hoffmann, H.-D., Kling, M. F., Apolonski, A.:
Direct low-harmonic generation in gas at MHz repetition rate
Lasers and Electro-Optics Europe (CLEO EUROPE/IQEC)
Conference on and International Quantum Electronics Conference, Munich 12-16 May 2013 (1 S.) (2013)
https://doi.org/10.1109/CLEOE-IQEC.2013.6800880

Büsing, L., Bonhoff, T., Gottmann, J., Loosen, P.:
Deformation of ultra-short laser pulses by optical systems for laser scanners
Opt. Expr. 21 (21), 24475-24482 (2013)
https://doi.org/10.1364/OE.21.024475 (Open Access)

Carstens, H., Holzberger, S., Kaster, J., Weitenberg, J., Pervak, V., Apolonski, A., Fill, E., Krausz, F., Pupeza, I.:
Large-mode enhancement cavities
Opt. Expr. 21 (9), 11606-11617 (2013)
https://doi.org/10.1364/OE.21.011606 (Open Access)

Finger, J., Weinand, M., Wortmann, D.:
Ablation and cutting of carbon-fiber reinforced plastics using picosecond pulsed laser radiation with high average power
J. Laser Appl. 25, (4), 042007-1 (5 S.) (2013)
https://doi.org/10.2351/1.4807082

Pupeza, I., Holzberger, S., Eidam, T., Esser, D., Weitenberg, J.,
Rußbüldt, P., Rauschenberger, J., Limpert, J., Udem, Th., Tünnermann, A., Hänsch, T. W., Apolonski, A., Krausz, F., Fill, E.:
Compact high-repetition-rate source of coherent 100 eV radiation
Nature Photonics 7, (8) 608-612 (2013)
https://doi.org/10.1038/nphoton.2013.156

Tulea, C., Caron, J., Wahab, H., Gehlich, N., Hoefer, M., Esser, D., Jungbluth, B., Lenenbach, A., Noll, R.:
Highly efficient nonthermal ablation of bone under bulk water with a frequency-doubled Nd:YVO4 picosecond laser
SPIE Photonics Europe, 2014, Brussels, Belgium. Proceedings Volume 9135, Laser Sources and Applications II; 91350C (2014)
https://doi.org/10.1117/12.2004392

Zhuang, F., Jungbluth, B., Gronloh, B., Hoffmann, H.-D., Zhang, G.:
Dual-wavelength, continuous-wave Yb:YAG laser for high-resolution photothermal common-path interferometry
Appl. Opt. 52 (21), 5171-5177 (2013)
https://doi.org/10.1364/AO.52.005171

Gronloh, B., Russbueldt, P., Schneider, W., Jungbluth, B., Hoffmann, H.-D.:
High average power sub-picosecond pulse generation at 515 nm by extracavity frequency doubling of a mode-locked Innoslab MOPA 
Proc. SPIE 8235, 10 S., (2012)
https://doi.org/10.1117/12.908053

Reininghaus, M., Wortmann, D., Finger, J., Faley, O., Poprawe, R., Stampfer, C.:
Laser induced non-thermal deposition of ultrathin graphite
Appl. Phys. Lett. 100, Nr. 15, 1-3, (2012)
https://doi.org/10.1063/1.3703599

Wortmann, D., Koch, J., Reininghaus, M., Unger, C., Hulverscheidt, C., Ivanov, D., Chichkov, B. N.:
Experimental and theoretical investigation on fs-laser-induced nanostructure formation on thin gold films
J. Laser Appl. 24, 4 (Special ed). 6 S. (2012)
https://doi.org/10.2351/1.4734048

Wueppen, J., Nyga, S., Taubner, T., Jungbluth, B.:
Ultrafast mid-IR laser source with a tuning range from 9 to 16 microns based on nonlinear frequency conversion
In: mirsens2, International Workshop on Opportunities and Challenges
in Mid-Infrared Laser-Based Gas Sensing, October 18-20, 2012, Wroclaw
pp. 18-19 (2012)
http://dx.doi.org/10.1109/irmmw-THz.2011.6104904

Mans, T., Dolkemeyer, J., Russbüldt, P., Schnitzler, C.:
Highly flexible ultrafast laser system with 260W average power 
Proc. SPIE 7912, 79120M, 6 S., (2011)
http://dx.doi.org/10.1117/12.874417

Russbueldt, P., Hoffmann, H.-D., Mans, T., Poprawe, R.:
1100 W Yb:YAG femtosecond Innoslab amplifier
Proc. SPIE 7912, 79120R, 9 S., (2011)
https://doi.org/10.1117/12.878472

Schulz, M., Riedel, R., Willner, A., Mans, T., Schnitzler, C., Russbueldt, P., Dolkemeyer, J., Seise, E., Gottschall, T., Hädrich, S., Duesterer, S., Schlarb, H., Feldhaus, J., Limpert, J., Faatz, B., Tünnermann, A., Rossbach, J., Drescher, M., Tavella, F.:
Yb:YAG Innoslab amplifier: efficient high repetition rate subpicosecond pumping system for optical parametric chirped pulse amplification 
Opt. Lett. 36, Nr. 13, 2456-2458, (2011)
https://doi.org/10.1364/OL.36.002456

Weitenberg, J., Rußbüldt, P., Eidam, T., Pupeza, I.:
Transverse mode tailoring in a quasi-imaging high-finesse femtosecond enhancement cavity 
Opt. Expr. 19, Nr. 10, 9551-9561, 2011
https://doi.org/10.1364/oe.19.009551 (Open Access)

Rußbüldt, P., Mans, T., Weitenberg, J., Hoffmann, H. D., Poprawe, R.
Compact diode-pumped 1.1 kW Yb:YAG Innoslab femtosecfond amplifier
Opt. Lett. 35; Nr 24, 4169-4171, (2010)
https://doi.org/10.1364/OL.35.004169

Gronloh, B., Höfer, M., Wester, R., Hoffmann, H.-D.:
High power UV generation at 355 nm by means of extracavity frequency conversion of a high repetition rate Innoslab MOPA system
Proc. SPIE 7193, 71930Y, 11S., (2009)
https://doi.org/10.1117/12.813633

Mans, T., Rußbüldt, P.:
Höchste mittlere Leistung für Ultrakurzpulslaser
LASER+PHOTONIK Nr. 3, 20-24, (2009)

Wortmann, D., Mans, L., Weitenberg, J.:
Multi-100 W average power fs-laser for material processing applications
ICALEO 2009, 28th Int. Congr. on Applications of Lasers & Electro-Optics, November 2-5, 2009, Orlando, Fl.
paper M101, pp. 856-860, (2009)
https://doi.org/10.2351/1.5061654

Mir, M. , Gutknecht, N. , Poprawe, R., Vanweersch, L., Lampert, F.:
Visualising the procedures in the influence of water on the ablation of dental hard tissue with erbium:yttrium-aluminium-garnet and erbium, chromium:yttrium-scandium-gallium-garnet laser pulses
Lasers Med. Sci. 24, 365-374, (2009)
https://doi.org/10.1007/s10103-008-0571-1

Mans, T., Rußbüldt, P., Weitenberg, J.
Yb :KYW Innoslab-Amplifier
Conference on Lasers and Electro-Optics 2009 and the European Quantum Electronics Conference. CLEO Europe - EQEC 2009, Munich, 14-19 June 2009
Mulhouse: European Physical Society, paper CA3_2, 1 S., (2009)

Rußbüldt, P., Mans, T., Rotarius, G., Weitenberg, J., Hoffmann, H.D., Poprawe, R.:
400 W Yb:YAG Innoslab fs-amplifier
Opt. Expr.17(15), 12230-12245, (2009)
https://doi.org/10.1364/OE.17.012230 (Open Access)

Russbueldt, P., Mans, T., Hoffmann, D. ,Poprawe, R.
High Power Yb:YAG Innoslab fs-Amplifier
Proceedings of the Conference on Lasers and Electro-Optics & Quantum Electronics and Laser Science Conference (CLEO), May 4-9, 2008, San Jose, California
Vortrag CTuK5, 2 S., (2008)
https://doi.org/10.1109/CLEO.2008.4551698