Interview with Fellows

“The concept of resonance-enhanced supercontinuum generation is highly relevant for future nonlinear light sources”. Interview with MULTIPLY Fellow Xue Qi

Xue Qi received her Ph.D. degree in Optical Engineering from National University of Defence Technology (Changsha, P. R. China) in December 2017. Her doctoral thesis was focused on high-power visible-enhanced supercontinuum generation in a seven-core photonic crystal fibre. In 2019, she joined the Leibniz Institute of Photonic Technology (Jena, Germany) as a postdoc to continue the study of ultrafast pulse propagation and soliton dynamics in specialty fibres. Her MULTIPLY project is to study the mechanisms of supercontinuum generation based on dispersion tuning via geometry induced resonance. We asked Xue to tell us more about her research.

During your MULTIPLY Fellowship, you work with Prof.Markus Schmidt. What research skills have you acquired during these months?
During this time, I have acquired new experimental skills in the aspects of supercontinuum system development using fluid-filled hybrid fibers, fiber tapering, and 3D printing techniques. Except that, I also learned some complementary skills, such as how to writing a proposal, how to supervise a student and project management, etc.

What question or task did you set yourself before starting this work?
We want to study the fundamental physics about how the geometry-induced resonance (for example, gas-filled anti-resonant hollow-core fiber) affects the dispersion and broadband supercontinuum generation, and also hope to demonstrate the power scalability of supercontinuum generation in liquid/gas filled anti-resonant hollow-core fibers.

What have you already achieved?
We have already revealed the nonlinear dynamics of soliton-based supercontinuum generation in case the waveguide includes a strongly dispersive resonance numerically and experimentally in a liquid strand-based photonic bandgap fiber.

Why is your research important? What are the possible real-world applications?
Because a high-energy ultra-broad coherent supercontinuum is highly desirable in great various areas, such as quantum metrology, nonlinear physics and time-resolved spectroscopy. Besides, the concept of resonance-enhanced supercontinuum generation is highly relevant for future nonlinear light sources.

What is your favorite aspect of your research?
My favorite aspect is to explore the physics mechanism of how the strong dispersion variation induced by the geometry-induced resonance influence the supercontinuum generation and to design a suitable experimental platform to prove it.

What was your most surprising scientific finding?
The most surprising finding, from my side, is that we find the critical parameter that determines whether dispersive waves can be generated across the resonances (i.e., high attenuation regions) between different photonic bandgaps. This finding can give some insights into the fiber design in the future to realize the interband dispersive wave generation.

Your MULTIPLY Project had been extended for several months due to Covid. Have you set yourself some new goals for these months?
Yes, I have a new goal. I want to explore new dispersion-management means to realize ultra-broad coherent supercontinuum generation with improved flatness, which is important in real-world applications, like bioimaging and microscopy.