Ultrafast Nonlinear Optics team

Mid-IR supercontinuum generation in an LIS crystal

The Ultrafast Nonlinear Optics (UNO) team focuses on nonlinear optics with ultrafast laser pulses on a femtosecond time scale.

About the team

In the Ultrafast Nonlinear Optics team we investigate nonlinear optical phenomena with ultrafast femtosecond pulses, where the excitation of temporal solitons in bulk media or optical waveguides and fibers allow achieving efficient frequency conversion, pulse compression and supercontinuum generation. Our main focus is solitons generated in quadratic nonlinear crystals through cascaded (phase-mismatched) frequency conversion processes. This gives access to a unique self-defocusing nonlinearity that has many advantages compared to traditional self-focusing four-wave mixing processes, in particular that it is inherently filament free. We are currently exploring new opportunities in the mid-IR range (2-20 micron) for supercontinuum generation and pulse compression of high energy pulses (in bulk crystals) or high-repetition rate low energy pulses (waveguides). We also investigate new hollow-core fibers for broadband handling, transmission and nonlinear interaction of near to mid-IR pulses in gas-filled fibers.


  1. First theoretical explanation of the nonlocal nature of ultrafast cascaded nonlinearities (Bache et al. OL 2007)
  2. First theoretical prediction of optical Cherenkov radiation in ultra-fast cascaded second-harmonic generation (Bache et al. PRA 2010)
  3. First experimental observation of filament-free soliton-induced octave-spanning supercontinuum using nonresonant defocusing cascaded nonlinearities (Zhou et al. PRL 2012)
  4. First noncritical (type 0) soliton compression experiment with defocusing cascaded nonlinearities (Zhou et al. PRL 2012)
  5. First experimental observation of resonant nonlocal response with defocusing cascaded nonlinearities (Zhou et al. PRA 2014)
  6. First experimental observation of octave-spanning supercontinuum generation in an unpoled quadratic nonlinear waveguide (Guo et al. OL 2015)
  7. First experimental observation of mid-IR optical Cherenkov radiation with defocusing cascaded nonlinearities (Zhou et al. OE 2015
  8. First experimental observation of mid-IR pumped mid-IR supercontinuum with defocusing cascaded nonlinearities (Zhou et al. APL Photonics 2016)
  9. First theory and experimental observation of resonant radiation (optical Cherenkov waves) through three-wave mixing terms (Zhou et al. PRL 2017)

Team leader

Morten Bache
DTU Fotonik
+45 45 25 37 75




March 2018: On March 23, 2018, Morten Bache defends his doctor technices thesis (pdf)

September 2017: New paper in J. Opt. - M. Bache and A. Lavrinenko, Ultrafast nonlinear dynamics of thin gold films, Journal of Optics 19, 094004 (2017), online

May 2017: New paper in OL - Md. S. Habib, C. Markos, O. Bang, and M. Bache, Soliton-plasma nonlinear dynamics in mid-IR gas-filled hollow-core fibers, Optics Letters 42, 2232-2235 (2017), online

April 2017: New paper in PRL - B. B. Zhou, X. Liu, H. R. Guo, X. L. Zeng, X. F. Chen, H. P. Chung, Y. H. Chen, and M. Bache, Parametrically Tunable Soliton-Induced Resonant Radiation by Three-Wave Mixing, Phys. Rev. Lett. 118, 143901 (2017), online

April 2017: Gaoyuan Li and Simon Christensen started their PhD projects

February 2017: Shreesha Rao started his PhD position  

December 2016: New paper - M. Klimczak, B. Siwicki, B. Zhou, M. Bache, D. Pysz, O. Bang, and R. Buczyński, Coherent supercontinuum bandwidth limitations under femtosecond pumping at 2 µm in all-solid soft glass photonic crystal fibers, Opt. Express 24, 29406-29416 (2016), online

November 2016: New paper - O. Lysenko, M. Bache, N. Olivier, A.V. Zayats, and A. Lavrinenko, Nonlinear Dynamics of Ultrashort Long-Range Surface Plasmon Polariton Pulses in Gold Strip Waveguides, ACS Photonics 3, 2324-2329, (2016), online

August 2016: 15 Phd positions announced across Europe for the SUPUVIR project, read more here.

July 2016:  X. Liu et al. Octave-spanning supercontinuum generation in a silicon-rich nitride waveguide, Optics Letters 41, 2719-2722 (2016) among July 2016 top downloads of Optics Letters. 

June 2016: New paper - B. Zhou and M. Bache, Multiple-octave spanning high-energy mid-IR supercontinuum generation in bulk quadratic nonlinear crystals, (invited), APL Photonics 1, 050802 (2016), [pdf]

June 2016: New paper - X. Liu, M. Pu, B. Zhou, C. J. Krückel, A. Fülöp, V. Torres-Company and M. Bache, Octave-spanning supercontinuum generation in a silicon-rich nitride waveguide, Optics Letters 41, 2719-2722 (2016), [pdf] 

June 2016: New paper - O. Lysenko, M. Bache and A. Lavrinenko, Nonlinear optical model for strip plasmonic waveguides, Journal of the Optical Society of America B 33, 1341-1348 (2016), [pdf]

May 2016: New grant - SUPUVIR - a Marie Curie training network on supercontinuum generation, coordinated by the Ultrafast Nonlinear Optics team

April 2016: Xing Liu defended his PhD thesis

April 2016: New paper - Md. S. Habib, O. Bang, and M. Bache, Low-loss single-mode hollow-core fiber with anisotropic anti-resonant elements, Optics Express 24, 8429-8436 (2016)[pdf]

January 2016: New paper - Md. S. Habib, O. Bang, and M. Bache, Low-loss hollow-core anti-resonant fibers with semi-circular nested tubes, IEEE Journal of Selected Topics in Quantum Electronics 22, 4402106 (2016), [pdf]

January 2016: New paper - O. Lysenko, M. Bache and A. Lavrinenko,Third-order susceptibility of gold for ultrathin layers, Optics Letters 41, 317-320 (2016), [pdf]

November 2015: New femtosecond OPO, regenerative amplifier and hollow-fiber compressor installed