Advisors

Ultrafast nonlinear optics in gas-filled PCF

By sending intense ultrashort laser pulses into hollow-core photonic crystal fibres filled with a variety of gases, extreme nonlinear effects can be observed. For example, the input laser pulses can self-compress in time, to become as short as a single optical cycle in duration. The corresponding increase in intensity and bandwidth provides the basis for some unique experiments [1]. For example, by tuning the gas pressure, ultrashort pulses in the deep-UV to visible spectral region (180-600 nm) can be emitted with high efficiency [2]. The extremely high electric fields at the temporal focus can cause photoionization of the gas, bringing plasma nonlinearities to fibre optics [3]. Among many fascinating effects, this can lead to solitons that blue-shift to high frequencies as they propagate along the gas-filled fibre. The investigation of ultrafast nonlinear optics in gas-filled PCF is a very new and rapidly expanding field. Planned experiments include ultrafast laser-plasma interactions inside fibre, generation of high-harmonics in the extreme-UV, generation of sub-femtosecond pulses with novel techniques and nonlinear optical effects in the mid-infrared.

References

  1. J. C. Travers, W. Chang, J. Nold, N. Y. Joly and P. St.J. Russell, Ultrafast Nonlinear Optics in Gas-Filled Hollow-Core Photonic Crystal Fibers, J. Opt. Soc. Am. B 28 (2011).
  2. N. Y. Joly, J. Nold, W. Chang, P. Hölzer, A. Nazarkin, G. K. L. Wong, F. Biancalana and P. St J. Russell, Bright Spatially Coherent Wavelength-Tunable Deep-UV Laser Source Using an Ar-Filled Photonic Crystal Fiber, Phys. Rev. Lett. 106, 203901 (2011).
  3. P. Hölzer, W. Chang, J. C. Travers, A. Nazarkin, J. Nold, N. Y. Joly, M. F. Saleh, F. Biancalana and P. St.J. Russell, Femtosecond Nonlinear Fiber Optics in the Ionization Regime, Phys. Rev. Lett. 107, 203901 (2011).

Figure: UV generation can be made visible even to the unaided eye. This process is accompanied by visible sidescatter - starting at the point of generation and moving along the rest of the fibre.

Contact:

Prof. Dr. John Travers (john.travers@mpl.mpg.de); Prof. Dr. Nicolas Joly (nicolas.joly@mpl.mpg.de)