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Discovery of optical of frequency comb (OFC) has revolutionized the field of metrology, thanks mainly to
its broadband spectra with very well-defined phase coherence [1]. In parallel, quantum features of light
have triggered not only fundamental physics studies but also application oriented research activities,
notably in metrology [2,3]. The central goal of my research work is merging these two very attractive fields
of optical physics to exploit the potential originating from the interplay between the intrinsic quantum
nature of light over broad spectra and at extreme time scales for metrological application as well as
exploration of fundamental aspects of quantum optics and laser physics. In the first part, I will focus on
classical metrology, particularly, measurement of parameter fluctuations in an OFC. In fact, noises in OFC
manifest themselves as fluctuations of only a few global parameters (power, center frequency, repetition
rate, carrier-envelop offset frequency) [4]. Furthermore, it turns out that each physical parameter of the
OFC can be associated with a unique time/frequency mode (pulse shape) of the pulsed laser light [4,5].
Thus by introducing a mode-sensitive measurement scheme that combines spectrally resolved detection
with homodyne, we succeeded to address all phase and amplitude noises of an OFC along with phase-
amplitude noise correlations in a single-shot measurement [6,7,8,9]. In the second part, I will discuss
quantum aspects of my research work in the context of one of our targeted metrological applications,
namely, space-time positioning. It has been shown that the combination of a pulsed light in a proper
time/frequency mode with the mode-sensitive measurement technique as described previously can lead to
optimal sensitivity in space-time positioning saturating Cramer-Rao bound [10,11]. Moreover, such a
modal approach prescribes that a squeezed light in the proper time/frequency modes paves the way
achieving sensitivity below standard quantum limit. I will introduce our experimental setup dedicated
towards generation and characterization of multimode squeezed light, and discuss applicability of such
source for quantum enhanced space-time positioning [12]. The source is based on parametric down
conversion process in a second-order nonlinear crystal pumped with an OFC. To conclude, I will present a
few other perspectives of such multimode squeezed light source, particularly in quantum information and
testing fundamental aspects quantum physics.
Reference
[1] T. Udem et al. Nature 416, 233 (2002).
[2] C. M. Caves, Phys. Rev. D 23, 1693 (1981).
[3] V. Giovannetti, et al. Phys. Rev. Lett. 96, 010401 (2006).
[4] H. A. Haus, et al. J. Opt. Soc. Am. B 7, 386 (1990).
[5] R. Schmeissner, et al. Phys. Rev. Lett. 113, 263906 (2014).
[6] S. De, et al. CLEO Europe (2017).
[7] S. De, et al. CLEO USA (2017).
[8] S. De, et al. Submitted to Nat. Photon. (2017).
[9] S. De, et al. In preparation (2017).
[10] V. Thiel, et al. Quantum Sci. Technol. 2, 034008 (2017).
[11] B. Lamine, et al. Phys. Rev. Lett. 101, 123601 (2008).
[12] S. De, et al. BIPM Workshop "The Quantum Revolution in Metrology", France, (2017). |