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)

Team leader

Morten Bache
DTU Fotonik
+45 45 25 37 75




December 2016: New PhD position available, read more here

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

December 2016: The call for the 2017 HC Ørsted Postdoc programme is online, please contact us if you are interested in applying.

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, posted

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