BAR ILAN
QUANTUM OPTICS

Mission: To harness the optical bandwidth resource for quantum optical science and technology.

 

We focus on both quantum and classical optics with broadband, highly multimode correlated light.  At the quantum level, we explore ultra-broadband squeezed light and time-energy entangled photons for applications of ultrafast quantum communication and squeezing-enhanced sensing. With classical optics, we explore the coherent dynamics of mode-locked pulsed lasers and coupled parametric oscillators towards new sources of frequency-combs and for precision ultrafast measurement.

With quantum light, we develop sources of ultra-broad quantum light, such as octave-spanning time-energy entangled bi-photons and multimode coherent squeezed light, along with methods of broadband quantum measurement that are compatible with these highly multimode sources, namely broadband parametric homodyne measurement and nonlinear quantum interference. We employ these sources and measurement methods to develop quantum technology of sensing and communication beyond the bounds of classical physics, while employing the multimode bandwidth to enhance the processing-throughput by orders of magnitude compared to the standard single-mode methods. Specifically, we develop a frequency-multiplexed version of continuous-variable QKD, where multiple QKD channels are encoded simultaneously on a single source of time-energy entangled bi-photons and decoded simultaneously with a single local oscillator by broadband parametric homodyne. We also develop squeezing-enhanced Raman spectroscopy to identify the chemical content of a sample by measuring simultaneously the complete Raman spectrum of the sample beyond the shot-noise limit. 

In the high power, classical regime, we explore the coherent dynamics in networks of coupled multimode oscillators in various scenarios: We analyze coupled parametric oscillators, which demonstrate a unique regime of persistent full-scale beating, and consider their relation to models of coupled Ising spins and to coherent computation. In lasers, we explore the spatio-temporal dynamics of mode-locking with a Kerr nonlinearity that leads to the formation of ultrashort pulses. We analyze in great detail, in both space and time, the multimode nonlinear dynamics  associated with the intra-cavity Kerr lens; and consider its applicability to new sources of ultrashort pulses, such as diode-based high-power mode-locked lasers.