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Seminar: Fiber-based SU(1,1) nonlinear interferometers and their applications

ABSTRACT

SU (1,1) nonlinear interferometers realized by replacing beam splitters of traditional interferometers with parametric amplifiers for wave splitting and mixing exhibit a number of advantages. On the one hand, the quantum interferometric method realized by SU(1,1) nonlinear interferometer can separate the control of mode structure from nonlinear interaction, and the mode structure of quantum states can be flexibility engineered. On the other hand, this type of quantum entangled interferometer has practical implication and significance in quantum sensing since the quantum enhanced signal-to-noise ratios in phase and amplitude measurements are less sensitive to the losses outside the interferometer.

In this talk, the parametric amplifiers of SU(1,1) nonlinear interferometers are realized by exploring the Kerr nonlinearity of silica core fibers compatible with the existing fiber networks.  Firstly, I will show our work on engineering the spectral property of quantum states by using fiber-based SU(1,1) nonlinear interferometers. Secondly, I will demonstrate the realization of loss tolerant quantum dense metrology and dual-beam sensing by using the nonlinear interferometers. Thirdly, I will present our investigations on the unbalanced SU(1,1) interferometer, in which we find the interference can be recovered by direct amplitude measurement using homodyne detection and subsequent addition in photo-currents. Finally, by extending the new mechanism of recovering interference to other unbalanced interferometers, I will show the experimentally observed quantum interference of single photons in distinguishable paths and discuss its potential applications.

 

BIOGRAPHY

Xiaoying Li received her bachelors degree and masters degree from Tianjin University in 1989 and 1998, respectively. She received her PhD degree in 2002 from Shanxi University, where she experimentally demonstrated quantum dense coding for continuous variables by using entangled state generated from optical parametric oscillators. From 2002 to 2005, she was a post-doctoral fellow at Northwestern University in United States, where she developed all fiber sources of entangled photon pairs at telecom band. She joined Tianjin University in 2005, and she is currently a chair professor in the School of Precision Instrument and Opto-Electronics Engineering. Her research areas mainly focus on quantum optics using various types of nonlinear media, including silica-core optical fibers, nonlinear crystals in optical resonators and waveguides on-chip.      

Event Details
Speaker
Prof. Xiaoying Li
Chair Professor, Tianjin University

Date & Time
18 October 2024 3 pm

Venue
G5-314, Yeung Kin Man Academic Building, City University of Hong Kong

Chair
Prof. Jeff Ou (34422825)
jeffou@cityu.edu.hk