Investigation of mid-IR soliton-based supercontinuum generation in liquid core fibers

• Applicant: Professor Dr. Markus A. Schmidt
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 404883725

• Final Report Year: 2023

Final Report Abstract

The generation of light at infrared wavelengths represents an important area of research from both the fundamental and application perspectives. For example, fingerprint spectroscopy can be used to detect and quantify minute amounts of substances. Crucial here is the provision of an efficient light source, which should provide tailored light with a high spectral density at maximum beam quality. One approach to realizing such a source is nonlinear interactions in optical fibers, often employing the fission of higher-order temporal solitons that radiate excess energy in the form of dispersive waves. This process can be selectively tuned by manipulating the waveguide dispersion. In this project, fibers with liquid cores – so-called liquid-core fibers – were investigated in terms of tailored and tunable infrared light generation using soliton-based supercontinuum generation. This type of fiber waveguide offers unique capabilities, one example being the noninstantaneous response. Prior to the start of the project, it was reported that inorganic liquids in principle provide broad transmission windows for wavelengths >2µm and unique dispersion tuning capabilities that specifically result from the presence of a liquid core. Therefore, the goal of this project was to expand the knowledge of liquid core fibers through experiments and simulations. From the material's science perspective, absorption spectroscopy was used to quantify the losses in the IR transmission windows. Moreover, step-index profiles with silica or fluoride glass as cladding material or fibers with microstructured claddings served as photonic waveguide platforms, which were partially characterized regarding dispersion using an implemented setup. It was successfully demonstrated that liquid-core waveguides can tailor infrared light using nonlinear frequency conversion. In addition to experiments related to spectral bandwidth and wavelength, it was additionally shown that besides geometrical influences, mode dispersion and thus output spectra can be tuned by using binary liquid mixtures, axial core diameter variation and temperature modifications. Overall, nonlinear frequency conversion processes at infrared wavelengths in liquid core fibers have been successfully investigated, and the corresponding knowledge base has also been substantially expanded regarding potential applications (the project was relevant to 16 publications). Future studies will address application-related issues, e.g. in the field of quantum technologies or life sciences, while other nonlinear effects may also be considered in the future.

Publications

• Impact of deuteration on the ultrafast nonlinear optical response of toluene and nitrobenzene. Optics Express, 27(21), 29491.
  Karras, Christian; Chemnitz, Mario; Heintzmann, Rainer & Schmidt, Markus A.
  
• Long-term stable supercontinuum generation and watt-level transmission in liquid-core optical fibers. Optics Letters, 44(9), 2236.
  Schaarschmidt, Kay; Xuan, Hongwen; Kobelke, Jens; Chemnitz, Mario; Hartl, Ingmar & Schmidt, Markus A.
  
• Tailoring modulation instabilities and four-wave mixing in dispersion-managed composite liquid-core fibers. Optics Express, 28(3), 3097.
  Junaid, Saher; Schaarschmidt, Kay; Chemnitz, Mario; Chambonneau, Maxime; Nolte, Stefan & Schmidt, Markus A.
  
• Ultrafast intermodal third harmonic generation in a liquid core step-index fiber filled with C2Cl4. Optics Express, 28(17), 25037.
  Schaarschmidt, Kay; Kobelke, Jens; Nolte, Stefan; Meyer, Tobias & Schmidt, Markus A.
  
• Supercontinuum generation in a carbon disulfide core microstructured optical fiber. Optics Express, 29(13), 19891.
  Junaid, Saher; Bierlich, Joerg; Hartung, Alexander; Meyer, Tobias; Chemnitz, Mario & Schmidt, Markus A.
  
• Attenuation coefficients of selected organic and inorganic solvents in the mid-infrared spectral domain. Optical Materials Express, 12(4), 1754.
  Junaid, Saher; Huang, Wenqin; Scheibinger, Ramona; Schaarschmidt, Kay; Schneidewind, Henrik; Paradis, Pascal; Bernier, Martin; Vallée, Réal; Stanca, Sarmiza-Elena; Zieger, Gabriel & Schmidt, Markus A.
  
• Axial dispersion-managed liquid-core fibers: A platform for tailored higher-order mode supercontinuum generation. APL Photonics, 7(11).
  Qi, Xue; Scheibinger, Ramona; Nold, Johannes; Junaid, Saher; Chemnitz, Mario & Schmidt, Markus A.
  
• Spectral tailoring of photon pairs from microstructured suspended-core optical fibers with liquid-filled nanochannels. Optics Express, 30(16), 29680.
  Afsharnia, Mina; Lyu, Zhouping; Pertsch, Thomas; Schmidt, Markus A.; Saravi, Sina & Setzpfandt, Frank
  
• Tailored Multi‐Color Dispersive Wave Formation in Quasi‐Phase‐Matched Exposed Core Fibers. Advanced Science, 9(8).
  Lühder, Tilman A. K.; Chemnitz, Mario; Schneidewind, Henrik; Schartner, Erik P.; Ebendorff‐Heidepriem, Heike & Schmidt, Markus A.
  
• Temperature‐Sensitive Dual Dispersive Wave Generation of Higher‐Order Modes in Liquid‐Core Fibers. Laser & Photonics Reviews, 17(1).
  Scheibinger, Ramona; Hofmann, Johannes; Schaarschmidt, Kay; Chemnitz, Mario & Schmidt, Markus A.