GRK seminars

In the GRK seminar we offer our doctoral researchers a platform to receive concentrated feedback which evaluates scientific achievements, stimulates new ideas, and prepares the doctoral candidates for competitive on-stage performances as young academics. The seminar usually runs on Fridays from 14:15 to 15:15 in the Auditorium of the Abbe Center of Photonics at the Beutenberg.

GRK doctoral Seminar WS 2018/2019

In this semester we are sharing the seminar with our Canadian partners via an online conferencing tool. The seminars run biweekly and are hosted each time by another GRK or Create reserach group. Each seminar starts with an introductory lecture by the hosting PI on the research field, the current projects and collaboration opportunities followed by presentations of 1-2 GRK / Create students working in the research group. 

March 21th 2019

  • Prof. Markus Schmidt, IPHT,  "Microstructured fibers: basics and applications"
  • Kay Schaarschmidt, "Third Harmonic Generation in liquid core and microstructured fibers"
  • Ramona Scheibinger, "Tunable supercontinuum generation in higher-order modes"
    4 pm Germany time / 10 am Canada time - Seminar room 1, Abbe Center of Photonics

February 21th 2019

  • Prof. Ulf Peschel, IFTO,  tba
  • Arstan Bisianov, tba
  • André Muniz, tba
    4 pm Germany time / 10 am Canada time - Seminar room 1, Abbe Center of Photonics

January 21st 2019

  • Prof. François Légaré, INRS-EMT,  tba
  • Élissa Haddad, tba
  • Reza Safaei, tba
  • 4 pm Germany time / 10 am Canada time - Seminar room 1, Abbe Center of Photonics

January 10th 2019

  • Prof. Stefan Nolte, IAP,  tba
  • Kim Lammers, tba
  • Alessandro Alberucci, tba
  • 4 pm Germany time / 10 am Canada time - Seminar room 2 (Aquarium), Abbe Center of Photonics

December 17th 2018

  • Prof. Réal Valée, COPL, Université Laval,  tba
  • Yigit Ozan Aydin, tba
  • Frederic Maes, tba
    4 pm Germany time / 10 am Canada time - Seminar room 1, Abbe Center of Photonics

December 11th 2018

  • Prof. Alex Fuerbach, Macquarie University, Sydney / Australia, "Mid-infrared fibre laser technology"
    Seminar room, Institute of Applied Physics

The mid-infrared region of the electromagnetic spectrum (2-20 μm) has attracted significant scientific and technological interest as all molecules have their ro-vibrational absorption lines in this wavelength range. Therefore, the mid-IR is usually referred to as the ‘molecular fingerprint’ region. Owing to the high-impact applications that result from the strong molecule-photon interaction, such as trace molecular detection for airport security screening and non-invasive breath analysis, research in mid-IR lasers and photonics has become one of the hottest topics in modern optics research over the last few years.
In this talk I will summarise our recent scientific breakthroughs towards the development of all-fibre laser sources based on fluoride-glass optical fibres. In particular I will focus on the direct femtosecond laser-inscription of in-fibre components like Bragg gratings and polarisers as well as on the generation of an ultrabroadband supercontinuum in the mid-IR via nonlinear spectral broadening in hybrid chalcogenide/polymer microwires.

December 6th 2018

  • Prof. Joyce Poon, University of Toronto, tba
  • Thomas Lordello, tba
  • Jack Xue, tba
    4 pm Germany time / 10 am Canada time - Seminar room 1, Abbe Center of Photonics

November 19th 2018

  • Prof. Li Qian, University of Toronto,  tba
  • Arash Riazi, tba
  • Changjia Chen, tba
    4 pm Germany time / 10 am Canada time - Seminar room 1, Abbe Center of Photonics

November 8th 2018

  • Prof. Peter Herman, University of Toronto,  tba
  • Ehsan Alimohammadian, tba
  • Gligor Djogo, tba
    4 pm Germany time / 10 am Canada time - Seminar room 1, Abbe Center of Photonics

October 22nd 2018

  • Prof. Jens Limpert, IAP,  "Ultrafast Fiber Lasers: status and prospects"
  • Evgeny Shestaev, "Towards Highly Carrier-Envelope Stable High-Power Few-Cycle Fiber Lasers"
  • Vittoria Schuster, "XUV Tabletop Interferometry"
    4 pm Germany time / 10 am Canada time - Seminar room 1, Abbe Center of Photonics

October 11th 2018

  • Prof. Thomas Pertsch, IAP,  "Nano & Quantum Optics @ Institute ofApplied Physicsin Jena"
  • Franz Löchner, "Second-Harmonic Generation from coupled resonator systems"
  • Najmeh Abbasirad, "A Fully Automated Dual-Probe SNOM for Characterization of Localized Optical Phenomena"
    4 pm Germany time / 10 am Canada time - Seminar room 1, Abbe Center of Photonic

GRK doctoral Seminar SS 2018

August 27th 2018

  • Hatef Dinparasti Saleh, PhD, Heriot-Watt University, Institute of Photonics and Quantum Science, Edinburgh, UK "Indications of spontaneous parametric downconversion from monolayer MoS2"
    Seminar room 1, Abbe Center of Photonics

    A solid-state medium of subwavelength thickness with strong optical nonlinearities, embedded into an optical cavity, would pave the way to integrated cavity quantum electrodynamics and among other things would allow to test analogues of the Dynamic Casimir Effect. Here we present a detailed study of the second order nonlinear susceptibility of 2D (mono-atomic layer) dichalcogenide MoS2 and explore its potential for spontaneous parametric down-conversion (SPDC), the amplification of vacuum fluctuations mediated by optical nonlinearity. We present a model of SPDC in MoS2 monolayers and show that our data are compatible with the theoretical estimation and expectation. We study the power dependence of the second harmonic generation (SHG) and IR signal. Power dependence of the SHG signal perfectly fits a typical quadratic function while the IR dependence has a linear fit. This completely matches the SDPC model and it also can be associated to the photoluminescence signal as well. We also investigate the IR signal emission from the MoS2 monolayer attached to the bulk crystal (few layers) with a spatial resolution of 2 μm. Additionally, we present the time-resolved data from both bulk and monolayer crystal. Although the observation of quantum correlations was prevented by electronic limitations, we show some indications of SPDC, based on polarization and lifetime measurements. We also discuss and characterise a new photoluminescence emission around 1500 nm, which is enhanced at the edges of multi-layer MoS2.

July 16th 2018

  • Prof. François Légaré, INRS-EMT, Varennes,  "Ultrafast laser science and biomedical imaging at ALLS"
    Auditorium, Abbe Center of Photonics

July 11th 2018

  • Prof. Michael Chini, University of Central Florida, USA "High-order Harmonic and Attosecond Spectroscopies"
    Lecture hall 2, Helmholtzweg 5

    The generation of coherent extreme ultraviolet and soft x-ray light pulses, with attosecond (10-18 s) temporal duration, has enabled a new window into the ultrafast dynamics of electrons in matter. In this lecture, I will explain how ultrashort pulsed femtosecond (10-15 s) lasers can be used to generate these attosecond bursts through high-order harmonic generation, as well as how the durations of the emitted pulses can be accurately characterized. Finally, I will describe new spectroscopic techniques based on high-order harmonic generation and attosecond pulses, which can be used to follow electron dynamics in the time domain.

July 6th 2018

  • Prof. Mihai E. Vaida, University of Central Florida, USA "Surface photoinduced and photocatalytic reactions for the generation of fuels"
    Lecture hall, Abbe Zentrum Beutenberg

    The reduction of fossil fuels and the serious environmental problems associated with their combustions stimulated the modern society to search for new forms of energy that are clean, renewable, cheap, safe, and a viable alternative to the fossil fuels. A very attractive approach is the production of so-called “solar fuels” using photocatalytic materials to convert solar energy into a form of chemical bonds, similar to photosynthesis produced by green plants. Photocatalytic decomposition of water into hydrogen and oxygen by means of visible light is an important prototype example. Another example is the photocatalytic reduction of carbon dioxide that leads to the formation of fuel molecules: methanol, methane, formaldehyde, etc. Moreover, the sunlight energy reaching Earth in one hour equals to the annual global consumption of energy. Therefore, converting just a small fraction of the solar energy into clean and renewable fuels would be a solution for both the energy needs and environmental problems produced by the combustion of fossil fuels. This lecture will focus on surface photoinduced and photocatalytic reactions for generation of storable fuels from sustainable inputs. Staring from the basic mechanism of a photocatalytic reaction, the lecture will continue on discussing photocatalytic materials, and concrete photocatalytic reaction such as generation of hydrogen via water splitting and hydrocarbons via carbon dioxide reduction. A particular emphasis will be placed on understanding the electronic structure of the photocatalyst as well as the molecular dynamics of the reaction. In the end, strategies to improve the efficiency of the photocatalytic materials will be discussed as well as novel techniques to investigate photocatalytic reactions.

GRK doctoral Seminar WS 2017/2018

January 9th 2018

  • Prof. Ignacio Cirac, Head of theory division at Max Planck Institute of Quantum Optics, Garching "Quantum optics with emitters in waveguides"
    Auditorium, Abbe Center of Photonics

    Recent progress in nano-fabrication and atomic physics allowes us to couple atoms (or other emitters) to structured waveguides. In this talk I will report on different opportunities that are opened up by those systems, including the observation of many-photon bound states, the preparation of Fock states, the simulation of long-range spin interacting models, or the observation of exotic features in collective decays.

December 8th 2017

  • Dr. Guoqing Chang, Ultrafast Optics and X-rays Division, Center for free electron laser (CFEL), Deutsches Elektronen-Synchrotron (DESY), Hamburg"Advanced ultrafast laser sources harnessing fiber-optic nonlinearities"
    Auditorium, Abbe Center of Photonics

    Propagation of strong femtosecond pulses inside an optical fiber causes fiber-optic nonlinearities and results in numerous interesting nonlinear optical phenomena. We employ fiber-optic nonlinearities to improve the performance of ultrafast fiber lasers. The resulting novel ultrafast laser sources promise important applications in multiphoton microscopy imaging and high-power mid-infrared frequency combs.

GRK doctoral Seminar SS 2017

September 29th 2017

  • Dr. Axel Rühl, Laser Components Department, Institute of Quantum Optics, Hannover "The Role of Nonlinearities in Low-Noise Ultrafast Fiber Lasers" 
    Auditorium, Abbe Center of Photonics

    Nonlinear effects not only play a dominant role in the formation and propagation of ultrashort laser pulses in optical fibers but also impact their noise and coherence properties. This lecture introduces the interplay between various linear and nonlinear effects during propagation of ultrashort pulses in optical fibers and discusses its impact on phase as well as amplitude noise. It covers passively mode-locked laser oscillators and their use as low-noise frequency combs, ultrafast fiber amplifiers as well as spectral broadening in highly nonlinear fibers.

September 22nd 2017

  • Mona Nissen, IPHT "Antiresonant hollow-core fibers for UV spectroscopy and nanoparticle analytics"  
    Auditorium, Abbe Center of Photonics

September 8th 2017

  • Ria Krämer, IAP "Fiber Bragg gratings for high power fiber lasers"  
    Auditorium, Abbe Center of Photonics

August 25th 2017

  • Guest Prof. Wataru Watanabe, Department of Electrical & Electronic Engineering, College of Science and Engineering, Ritsumeikan University, Japan " Micromachining of glass/plastic by femtosecond laser direct writing and phase imaging"  
    Auditorium, Abbe Center of Photonics

Femtosecond laser micromachining allows internal modifications inside transparent materials. In this seminar, we review our recent topics on femtosecond laser micromachining. We show the regeneration of volume gratings made inside PMMA by femtosecond laser writing. In the femtosecond laser welding, we demonstrate the welding of two substrates with an air-gap. The welding of PMMA by dendrite pattern of quenched melt was demonstrated. The welding between glass and copper with surface roughness was demonstrated. Finally, we show phase imaging and contrast imaging of structural modifications in glass.

July 28th 2017

  • Brenda Doherty, IPHT "Plasmonic Nanoprticles in Microstructured Optical Fibres as Detection Platforms"  
    Auditorium, Abbe Center of Photonics

July 14th 2017

  • Najmeh Abbasirad, IAP "A fully automated dual-probe scanning near-field optical microscopy technique"  
    Auditorium, Abbe Center of Photonics

June 2nd 2017

  • Robert Klas, IAP "Into the XUV - Fiber Laser based High Harmonic Sources" 
    Auditorium, Abbe Center of Photonics

May 5th 2017

  • Martin Gebhardt, IAP "Performance scaling of ultrafast 2 µm fiber laser systems"  
    Auditorium, Abbe Center of Photonics

GRK doctoral Seminar WS 2016

During the Winter semester 2016 the GRK seminar series featured basic lectures by the PIs of the GRK projects to widen the knowledge of our students. 

March 27th 2017

  • Prof. Ya CHENG, Shanghai Institute of Optics and Fine Mechanics (SIOM)  "Breaking the barriers of diffraction in femtosecond laser materials processing" 
    Zeiss-Saal, Fraunhofer IOF

Diffraction is a nature of light. With the diffraction, it is known that (1) a light beam cannot be focused into a spot much smaller than the wavelength of the light; (2) focusing with a low-NA lens will inevitably give rise to a longitudinal resolution much poorer than the transverse resolution; and (3) a Bessel beam is always featured with a series of significant sidelobes. We discuss how to deal with these issues in various applications of femtosecond laser materials processing.

March 17th 2017

  • Prof. Benjamin Dietzek, IPC "Photoactive Molecules and Materials Implications from Spectroscopy"
    Auditorium, Abbe Center of Photonics

March 3rd 2017

  • Dr. César Jáuregui, IAP  "Understanding of transverse mode instabilities in high power fiber lasers"
    Auditorium, Abbe Center of Photonics

February 3rd 2017

  • Prof. Christian Spielmann, IOQ "Nonlinear effects of guided high intensity light"
    Auditorium, Abbe Center of Photonics

January 20th 2017

  • Prof. Ulf Peschel, IFTO "On the manipulation of optical pulses in fiber systems"
    Auditorium, Abbe Center of Photonics

December 9th 2016:

  • Prof. Stefan Nolte, IAP "Processing of transparent materials by ultrashort laser pulses: fundamentals and applications"
    Auditorium, Abbe Center of Photonics

November 23rd 2016:

  • Prof. Markus Schmidt, IPHT "Microstructured optical fibers: an innovative base for photonic sensing and light generation"
    Auditorium, Abbe Center of Photonics

First introductory seminar

Our doctoral students presented the first results of their projects and an outline of the upcoming work.

July 15th, 2016:

  • Maximilian Heck  "Control of Light Propagation in Advanced Optical Fibers by Ultrashort Pulse Laser Structuring"
  • Franz Löchner "Second-Harmonic Generation in MoS2 Monolayers Coupled to Resonant Nanoantennas"
  • Evgeny Shestaev "CEP noise in high-power fiber laser systems"
  • Kay Schaarschmidt "Applications of Liquid-filled Single Mode Fibers"
  • Christoph Stihler "Transverse Mode Instabilities in High-power Fiber Lasers"

July 8th, 2016:

  • Lukas  Maczewsky "Photonic Anomalous Floquet Topological Insulator"
  • Rudrakant Sollapur "Multi-octave Spectral Broadening in Anti-Resonant Hollow-core Fibers"
  • Friedrich Fröbel "Modeling of Nonlinear Optics in Gas-filled Hollow-core Fibers"
  • Arstan Bisianov "PT-symmetric 2D light walk"