Colloquium: 2022-09

Optoelectronic oscillators in the single photon regime: dead time effects and polarization alignment with entangled photons

Rajarshi Roy

September 14, 2022 at 2:00 PM (video)

Abstract

Optoelectronic oscillators with time-delayed feedback are of interest for generating precise frequencies, waveforms with chaotic dynamics and for exploring the dynamics of networks of coupled nonlinear oscillators.  We will describe experiments with an optoelectronic oscillator where single photons are detected and one can watch the progression from shot noise to the birth of a chaotic attractor.  Detecting single photons in the mid-infrared wavelength range for fiber optic communications with avalanche photodiodes is of interest for many applications, and we explore how such photon counting experiments can be affected by after-pulsing and dead time effects.  Synchronization of remotely located oscillators with entangled photons is a challenging problem with weak light sources.  We examine the question of non-local polarization alignment and control in fiber from correlated measurements of entangled photons.

Speaker

Rajarshi Roy studied Physics at St. Stephen’s College in Delhi, India and received a PhD in Physics from the University of Rochester in 1981. His advisor was Leonard Mandel, from whom he learned to explore light-matter interactions with table-top experiments. The coexistence of randomness and determinism, and of coherence and chaos, has been his abiding interest for over four decades. He has advised over three dozen doctoral students at Georgia Tech (1982 – 1999) and the University of Maryland (1999 – present), and collaborated with engineers, mathematicians, and scientists from around the world on nonlinear dynamics and statistical physics. He has served as chair of the School of Physics at Georgia Tech (1996 – 1999) and Director of the Institute for Physical Science and Technology (2003 – 2014) at the University of Maryland. He is a professor in the Department of Physics and his laboratory is located in the Institute for Research in Electronics and Applied Physics. He was a visitor at Bell Labs in Murray Hill in the spring of 1987, a visitor at NIH in 2009 and 2014 and Benedict Distinguished Visiting Professor at Carleton College in 2020 for the fall semester. He is a fellow of the Optical Society of America (now Optica) and the American Physical Society

short link: https://go.nasa.gov/3vSgAbf