Herzlich willkommen …


GDCh Wissenschaftsforum Chemie
Sep 15 – Sep 18 ganztägig

Thema: „Chemie – das gemeinsame Element“

MBI Colloquium: Frequency combs for sensible sensing @ Max-Born-Institut, Max Born Hall
Sep 18 um 14:00

Prof. Dr. Jean-Claude Diels | University of New Mexico, Albuquerque, USA

Frequency combs have enjoyed quite some notoriety in the area of metrology. The marvels of technology has made it possible to stabilize lasers so that you can beat independently generated combs against each others. We have shown [1] that very sensitive phase sensors (sensitivity to <10-8 radian) can be made with unstabilized lasers generating dual frequency combs (an anathema for big laser manufactors: no expensive ultrafast electronics required!). That was unfunded/unfundable research since it did not include the word “quantum” in the proposals. Fortunately, the Schödinger equation is ubiquitous, and describes the operation of the laser generating two frequency combs. Thus the massive tools of quantum mechanics can be, and have been applied to this system for enhancing its sensitivity. This contributed to massive deforestation with the discovery of “exceptional point” enhancement of sensitivity. Unfortunately, we have shown [2, 3] that the phase amplification at exceptional points comes with a larger noise amplification, making the practical implementation of this concept questionable. The use of resonant dispersion inside the mode-locked cavity offers another interesting possibility to manipulate – and amplify – the phase response. Rather than to attempt amplification of the phase response, one can improve the performance by reducing the noise. Our best phase sensitivity achieved with unstabilized laser is only an order of magnitude above the quantum limit. We will show how squeezing techniques can be called to the rescue (nowadays, “squeezing” is not longer associated with hugs...). References [1] L. Arissian and J.-C. Diels. Intracavity phase interferometry: frequency comb sensors inside a laser cavity. Laser & Photonics Rev, 8:799–826, 2014. [2] Luke Horstman, Ning Hsu, James Hendrie, David Smith, and Jean-Claude Diels. Exceptional points and the active laser gyroscope. Photonics Research, submitted, 2019. [3] D. D. Smith, H. Chang, L. Horstman, and J.-C. Diels. Parity-time-symmetry-broken gyroscopes: lasing without gain and subthreshold regimes. Optics express, submitted, 2019.

ADLERSHOFER KOLLOQUIUM Analytik: New strategies for clinical analysis via dried matrix spots @ Bundesanstalt für Materialforschung und -prüfung (BAM), Gebäude 8.05 / Lecture Hall
Sep 19 um 14:00

In recent years, the use of dried matrix spots (DMS), in general, and of dried blood spots (DBS), in particular, has substantially increased. These clinical specimens are formed when depositing a few droplets of the biological fluid subject to analysis (e.g., blood) onto a suitable clinical filter paper. While this minimally invasive sampling technique was already proposed many years (1963) ago by Guthrie and Susi to screen newborns for phenylketonuria, in the last decade its use has been applied to many other situations.

The reasons for this are related to the different benefits that such strategy brings about. In addition to the small sample requirement (a few droplets) and the minimally invasive nature of this strategy, which is essential for instance when the target is a newborn, since venipuncture is not suitable for them, there are other significant benefits. In fact, it has been demonstrated that the resulting DBS, precisely since water has been removed, it is much more stable and several can be stored for at least months without the need of special refrigerators, therefore making DBS ideal for biobanks. Also, when screening of large areas in less developed countries is intended, this is a very attractive approach, as it enables sampling a large population with a mobile station and send the DBS to the lab by mail. In fact, for patients with chronic disorders, it is possible to obtain the DBS in their own houses and send them to the lab as well.

Despite all these benefits, there are some challenges associated with the analysis of these types of samples, particularly when quantitative information is aimed at. In this presentation, different ways to produce DBS will be introduced and compared, with the ultimately goal of obtaining elemental information.

… beim Forschungsnetzwerk des Technologieparks Adlershof, der IGAFA. Gegründet 1992, widmet sich die Initiativgemeinschaft Außeruniversitärer Forschungseinrichtungen in Adlershof e. V. – IGAFA – der Vernetzung von deutschen und internationalen Wissenschaftlerinnen und Wissenschaftlern aus dem universitären Bereich, den Forschungsinstituten und Unternehmen in Adlershof.