School of
Information Technology and Electrical Engineering

Speaker: Dr Romain Demur, The University of Sydney
Seminar Date: Fri, 11/10/2019 - 11:00
Venue: 49-502; AEB Seminar Room
Host: Dr Mickael Mounaix

Seminar Type: Guest Research Seminar


There is a wide range of applications in active infrared detection technologies in defense and security. Active imaging in the near-infrared for target detection and identification or remote spectroscopy in the mid-infrared are some of them. However, the limited range available by these systems limits their developments. Increasing sensors sensitivity is a key milestone to improve this range. Indeed, noise in infrared detectors is much higher than for visible detectors due to physical and technological issues.

Recent advances in optical crystals and pump laser regimes bring renewed interest to upconversion detection for some specific application cases presented in this talk. The conversion of the infrared signal to the visible spectrum allows us to use all the benefits of silicon-based sensors. We will focus on the conversion of near-infrared images for active imaging applications. The physical properties of the non-linear conversion – energy conservation and phase matching condition – limit the conversion capabilities of the spatially multimode signal. Using a special pump laser with a broadband spectrum, we overcome this limitation where different parts of the spectrum achieve different phase-matching conditions. Thus, we dramatically increase the number of converted modes.  

A key milestone of this work is the sensitivity improvement of such a detection. Sensitivities obtained are one order of magnitude better than with direct detection using common infrared sensors.


Dr Romain Demur is a Research Associate in nanophotonic in the School of Electrical and Information Engineering at The University of Sydney. He received an Engineering degree in Physics from Ecole Superieure de Physique et de Chimie Industrielle de la Ville de Paris (ESPCI Paris, France) in 2014 and a Master degree in Optical and Laser Science from Institut d’Optique (Palaiseau, France) in 2015. He completed his PhD on the topic “Upconversion detection for long-range active imaging in the infrared” in the Kastler Brossel Laboratory at Sorbonne University (Paris, France) and Thales Research & Technology (Palaiseau, France) in 2018. His expertise and skills stretch across the fields of lasers, non-linear optics, optical detection and nanophotonic from simulations to experiments for industrial applications. His current research focuses on the development of nanophotonic integrated LiDAR.