past events

Wednesday 18. April 2018

LECTURE ANNOUNCEMENT
Fabrication of perfect ultra-long fiber Bragg gratings for high-performance Raman fiber lasers

 

Organisation: Max Planck Institute for the Science of Light / Russell Division

Speaker: Sébastien Loranger, Ph. D. (Advanced Photonic Concept Laboratory, Ecole Polytechnique de Montréal, Canada)

Place: MPL / seminar room (1.500)

Abstract:

Distributed feedback (DFB) fiber laser constructed around a phase-shifted fiber Bragg grating (FBG) can achieve outstanding performance in terms of single-frequency operation with linewidth in the kHz range. Using Raman gain as pumping mechanism allows such laser to be operated in any band, including those where rare-earth cannot reach. However, due to the low Raman gain, ultra-long FBGs in highly non-linear small-core fiber must be fabricated for operation at modest pump powers (~ 1 W or less). Such gratings were, until recently, impossible to fabricate with reproducibility due to non-uniformity in specialty fibers. Ultra-long FBGs are typically defined as gratings of lengths longer than typical phase mask, hence >20 cm long. We have recently demonstrated a technique which involves a fiber characterization prior to fabrication, and thus allows for the inscription of perfect ultra-long FBGs in any imperfect fiber. The technique will be presented as well as its results. This fabrication technique has allowed for the extensive study and optimisation of Raman DFB fiber laser. The limitations (mostly thermal gradient along the fiber) were identified and understood and outstanding performance was demonstrated (350 mW pump threshold).

Friday 13. April 2018

LECTURE ANNOUNCEMENT
Controlled chemical reactions with cold ions

 

Organisation: Max Planck Institute for the Science of Light / Leuchs Division

Speaker: Amir Mohammadi (Institut für Quantenmaterie, Universität Ulm)

Place: MPL / library (2.500)

Abstract:

Cold trapped ions are considered as quantum simulators that give a better understanding of the quantum world. From investigating the coherence of a quantum system to the entanglement to using as a quantum bit to make controlled chemical reactions at the level of a single particle are a wide range of applications of cold ions. In last few years, by combining the cold ions with ultracold atoms, a novel field has been created which study the reactions of atom-like particles at very low temperatures. In this talk, I present recent achievements in creating cold molecular ions by controlling the reaction parameters associated with the atom-ion system.

Monday 09. April 2018

IMPRS soft skill course
Project Management

 

Place: Light Lounge (third floor) at MPL

Time frame:

  • Monday April 9th from 9:00 a.m. until 6 p.m.
  • Tuesday April 10th from 8:00 a.m. until 12:30 p.m.

Coach: Rüdiger Herbst (ChallengeLearning)

Participants: Have already registered

More information:

The four phases of a project will be gradually developed and applied based on learning units, practical exercises and work on own projects. Thus the participant will gain a basic understanding of the work in a project, of the individual phases and which points are of major importance to work in a project. Reference will be made to different project management methods and with that it will be ensured that the individual tools can be used in different types of projects at the right places.

Content:

  • Project management overview
  • 4 phases of project management (main issues)

    • Initialization (project clarification, goals, project charter)
    • Planning (project structure planning, project procedure planning, risk management, resource management)
    • Realization (project controlling, change request management)
    • Closure (lessons learned)

  • Meetings and communication within a project

Goals:

  • To provide basic knowledge of project management - What to do and when?
  • Getting to know the important tools of project management - Which tool do I use when?
  • Learning and basic understanding of different project management methods - Where does project management take place and how does that fit to the basics?
Thursday 29. March 2018

IMPRS monthly meeting

 

Organisation: Ramin Beravat (MPL/ Russell Division)

What: Talk about "How to find a job" by Ramin

Where: MPL, Library (room 2.500, 2nd floor)

Friday 23. March 2018

LECTURE ANNOUNCEMENT
Dissipation of multi-partite systems under structured environments

 

Organisation: Max Planck Institute for the Science of Light / Genes Research Group

Speaker: Fernando Galve (Institute for Interdisciplinary Physics and Complex Systems, IFISC (CSIC-UIB))

Place: MPL / library (2.500)

Abstract:

We first review the transition of collective to separate (or local) dissipation in multi-partite systems under structured environments. Introducing a microscopic model of environment such as a periodic lattice, the transition is seen to be governed by the cross-damping coefficient, which can display long-range isotropic, directional long-range (dependent on crystal symmetry axes and orientation), and short-range behaviors depending on resonance conditions, but never on the bath's correlation length. We also find a frequency cutoff dependent only on system size. Next, we translate this scenario to atoms radiatively coupled through 2D photonic crystals, showing that purely directional emission is possible from FDTD simulations. We use this behavior, together with recently introduced reflective boundaries, to show how a variety of dark states of many atoms can be built. Finally we comment on recent results where we show that purely coherent directional interactions can be designed.

 

 

 

 

 

Monday 12. March 2018

LECTURE ANNOUNCEMENT
Squeezing vacuum with Rb atoms: quantum enhanced magnetometry and competition of spatial modes

 

Organisation: Max Planck Institute for the Science of Light / Leuchs Division

Speaker: Prof.  Eugeny Mikhailov (Department of Physics College of William & Mary Williamsburg, USA)

Place: MPL / seminar room 1.500

Friday 23. February 2018

LECTURE ANNOUNCEMENT
Digital electronic analysis, synthesis, and manipulation of the full optical field

 

Organisation: Max Planck Institute for the Science of Light / Russell Division

Speaker: Dr Peter Winzer, Director (Optical Transmission Subsystems Research, NOKIA Bell Labs, Crawford Hill, USA)

Place: MPL / seminar room 1.500

Abstract:

Optical communication systems have seen fundamental technological changes over the past 10 years that have completely redefined our ability to analyse, synthesize, and manipulate optical fields across all their physical dimensions: time/frequency, quadrature, polarization, and spatial mode content. State-of-the-art optical capabilities include stable low-linewidth lasers, programmable GHz-resolution optical filters, and spatial light modulators. Electronics capabilities include digital coherent subsystems based on high-speed (up to 100-GHz) analog-to-digital and digital-to-analog converters, and digital electronic signal processors based on Field Programmable Gate Arrays that can handle a Tbit/s of real-time data. These capabilities are about to fundamentally blur the boundaries between optical and electronic signal processing, asking for a combined view on optics and high-speed digital electronics in the analysis, synthesis, and manipulation of the full optical field, and enabling radically new opportunities across a wide range of photonics disciplines. After reviewing modern digital coherent detection and space-division multiplexing using multiple-input-multiple-output (MIMO) processing to scale fiber-optic network capacities, with new levels of physical-layer security as a by-product, we will take a glimpse at the vast possibilities enabled by fully digital light manipulation outside of telecom, from optical coherence tomography to endoscopic imaging to arbitrarily nonlinear and time-variant interferometry to ultra-fast optical tweezers.

Thursday 22. February 2018

LECTURE ANNOUNCEMENT
Subradiance and Selective Radiance in Atomic Arrays

 

Organisation: Max Planck Institute for the Science of Light / Genes Research Group

Speaker: Mariona Moreno-Cardoner, ICFO (Institute of Photonic Science), Barcelona, Spain

Place: MPL / seminar room 1.500

Abstract:

Achieving controlled coherent interactions between photons and atomic media is a central goal in quantum optics, and essential for many applications in quantum information processing and quantum metrology. Spontaneous emission, in which photons are absorbed by atoms and then re-scattered into undesired channels poses a fundamental limitation in all these tasks. In typical theoretical treatments of atomic ensembles, it is assumed that this re-scattering occurs independently, and at a rate given by a single isolated atom, which in turn gives rise to standard limits of fidelity in applications such as quantum memories for light or photonic quantum gates. However, this assumption can be in fact dramatically violated. In particular, it has long been known that spontaneous emission of a collective atomic excitation can be significantly enhanced or suppressed through strong interference in emission between atoms — the physics of super- and sub-radiance. While these concepts are not new, the physics underlying these effects have not been completely understood. 

In this talk we will first discuss a theoretical framework that captures multiple scattering and interference of light while propagating through the atoms [1]. Using this formalism, we will then show how sub-radiant states in a periodic atomic chain acquire an elegant interpretation in terms of optical modes that are “guided” by the array, which only emit due to scattering from the boundaries of the finite system. Then, we will introduce the new concept of selective radiance. Whereas sub-radiant states experience a reduced coupling to all optical modes, selectively radiant states are tailored to simultaneously radiate efficiently into a desired channel and to suppress emission into undesired directions, thus enhancing the atom-light interface. We will show that these states naturally appear in chains of atoms coupled to nanophotonic structures. As a relevant application of how they can be exploited, we will show that selectively radiant states allow for a photon storage error that performs exponentially better with number of atoms than previously known bounds.

[1] A. Asenjo-Garcia, J. D. Hood, D. E. Chang, H. J. Kimble, Phys. Rev. A 95, 033818 (2017).

[2] A. Asenjo-Garcia, M. Moreno-Cardoner, A. Albrecht, H. J. Kimble, D. E. Chang, Phys. Rev. X 7, 031024 (2017).

Thursday 22. February 2018

IMPRS monthly meeting
Tour at INTEGO

 

Organisation: Marc Pleinert (FAU/ Institute of Optics, Information and Photonics)

What: Tour at INTEGO (develops and produces camera inspection systems)

Where: Henri-Dunant-Str. 8, 91058 Erlangen

What else: Please register for the tour by filling out the doodle (link has been sent by e-mail) until February 14th!

Thursday 15. February 2018

LECTURE ANNOUNCEMENT
Firmengründungen durch Inkubation im Bereich der Photonik - erste Ergebnisse und Erfahrungen

 

Organisation: Max Planck Institute for the Science of Light / Leuchs Division

Speaker: Prof. Dr. G. Marowsky (Laser Laboratorium Göttingen

Place: MPL / room A.2.500