LMI Seminar:

Tackling longstanding challenges in ultrafast nonlinear optics via foreign but familiar physics

Prof. Jeffrey Moses

School of Applied and Engineering Physics,

Cornell University NY

Sunday December  11^th,  2022

13:00-14:00

Light refreshments and drinks will be served at 12:30

Auditorium 011, Engineering Classroom Building,  Faculty of Engineering, Tel-Aviv University

Abstract:

Optical nonlinearities have expanded the optics and photonics toolset for applications as diverse as high intensity laser science, quantum information processing, and the imaging and spectroscopy of biological systems. Key to many applications is use of the nonlinear polarizability of materials to couple photons between optical fields, giving rise to amplification and frequency conversion methods that expand the reach of lasers and other photon sources, both classical and non-classical. Other applications use light 'self-effects' to guide, switch, and modulate. However, optical nonlinearities are often small, and even when large enough, the spatiotemporal and spectral inhomogeneities in nonlinear optical systems can severely hamper the efficiency and bandwidth of power flow between waves. 
 
Our group has been seeking ways to 'trick' nonlinear systems into modes of evolution that can avoid the normal limiting behaviors or to make use of unconventional nonlinear interactions. I will discuss two examples that possess familiar physics that are somewhat foreign to optical light pulses. First, I will discuss how hybridized nonlinear processes can be used to achieve dissipative, non-Hermitian-like dynamical behavior in parametric frequency conversion despite no loss, and how this can be used to overcome a longstanding barrier to efficient parametric amplification. Second, I will discuss the phenomenon of optical polarizability involving coherent phonon coupling, which we predict gives rise to a giant Raman scattering susceptibility and a new way to control the optical properties of materials with mid-IR and THz light.

Bio:

Jeff Moses joined the faculty at Cornell University in 2014, where he leads the Ultrafast Phenomena and Technologies Group in the School of Applied and Engineering Physics. He received his B.S. from Yale University and Ph.D. from Cornell University, with both degrees in applied physics, and spent 2007-2014 at the Optics & Quantum Electronics Group in the Research Laboratory of Electronics at MIT as a postdoctoral associate and research scientist. He has received the US National Science Foundation CAREER award and was an US Air Force Office of Scientific Research Young Investigator.

School of Mechanical Engineering Seminar
Wednesday, January 11, 2023 at 14.00
Wolfson Building of Mechanical Engineering, Room 206

Searching for Satisficing Concepts under Multiple Objectives

Shai Alexandroni

M.Sc. student of Dr. Amiram Moshaiov

The Computational Intelligence Research Group

Concept selection is one of the critical decisions of the engineering design process. However, decision-making during the conceptual design stage is challenged by the large variety of possible designs, high uncertainties, and the biases of the Decision Makers (DMs). Thus, computer-supported conceptual design methods have been suggested in recent years. One such method is the Window-of-Interest based Satisficing Concept Search (WoISCS). This method involves the representation of a conceptual solution as a set of particular solutions and on predefined performance requirements. These requirements are presented as a set of acceptable performance vectors which has been termed Window-of-Interest (WoI). A concept is considered as satisficing if it is associated with at least one particular solution that has a performance vector within the WoI. Prior to this study, WoISCS has been researched to a limited extent, and only one dedicated search algorithm, which is termed WoISR, has been suggested in the literature.

The current research goal is to develop and compare new search algorithms for WoISCS. First, dedicated methods and tools are developed for evaluating WoISCS algorithms. Then, a first attempt on algorithm development is carried out by repurposing of existing Multi-Objective Evolutionary Algorithms (MOEAs), which were originally designed for Pareto optimization. A total of eight MOEAs were tested and compared to WoISR. The MOEAs performed surprisingly well, and some were comparable to the dedicated WoISR algorithm. Subsequently, a novel algorithm for WoISCS was developed based on the lessons of the MOEAs evaluation. The new algorithm was tested and compared to the other algorithms. Based on the numerical experiments it has been statistically inferred that the proposed algorithm outperforms both WoISR and the MOEAs in nearly all the test problems.

Join Zoom Meeting

https://tau-ac-il.zoom.us/j/4962025174?pwd=bVJUeElXRUUya3BERisyNllLOE9EZz09

סטודנטים וסטודנטיות, חברת אינטל מזמינה אתכם.ן להרצאת אונליין מרתקת !

אבי סלמון, מנהל החדשנות והיזמות באינטל ישראל, הולך לצלול לאחד הנושאים החשובים והמסקרנים (ספוילר – תציצו בשם ההרצאה) שבטח מעסיקים אתכם.ן בתקופה הזו בחיים (ואם לא- אז כדאי).

לפרטים נוספים והרשמה

(The talk will be given in English)

Speaker:  Dr. Anatoly Khina

School of Electrical Engineering, Tel Aviv University

 011 hall, Electrical Engineering-Kitot Building 

Monday, November 28^th, 2022

15:00 - 16:00

The Information Velocity of Packet-Erasure Links

Abstract

What is the maximal speed—the information velocity—at which information can propagate reliably in a network through a cascade of links? 

Information theory tells us what is the maximal rate of reliable communications through a small number of such links when delay is not important. However, if we want to communicate in real time, answering this question becomes much more challenging. In fact, even for the simple case of transmitting a single bit over a tandem of links, where each flips its input independently (across time & links), an answer was given only very recently.

In this talk, I will present some recent results for this problem for packet-based links with ACK signals. In particular, I will derive the information velocity for a causally arriving stream of packets, and determine the arrive-failure exponential decay rate below the information velocity.

No prior knowledge of information theory or queueing theory will be assumed.

Joint work with Elad Domanovitz & Tal Philosof.

Short Bio

Anatoly Khina is a faculty member in the School of Electrical Engineering, Tel Aviv University, Tel Aviv, Israel, from which he holds B.Sc. (summa cum laude, 2006), M.Sc. (summa cum laude, 2010), and Ph.D. (2016) degrees, all in Electrical Engineering. Parallel to his studies, he worked as an engineer in various roles focused on algorithms, software and hardware R&D. He was a Postdoctoral Scholar in the Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, USA, from 2015 to 2018, and a Research Fellow at the Simons Institute for the Theory of Computing, University of California, Berkeley, Berkeley, CA, USA, during the spring of 2018. His research interests include information theory, communications, statistics, control theory, and signal processing.

He is a recipient of the Fulbright, Rothschild and Marie Skłodowska-Curie Postdoctoral Fellowships; Clore Scholarship; Trotsky Award; Weinstein Prize in signal processing; Intel award for Ph.D. research; and the first prize for outstanding research work in the field of communication technologies from the Advanced Communication Center's Feder Family Award program.

השתתפות בסמינר תיתן קרדיט שמיעה = עפ"י רישום שם מלא + מספר ת.ז. בטופס הנוכחות שיועבר באולם במהלך הסמינר