Quantum Optics Seminar by G. Muñoz-Matutano

Fiber optics spectroscopic tools to study single quantum dot optical emission 

New optical fiber based spectroscopic tools open the possibility to develop more robust and efficient characterization experiments. Spectral filtering and light reflection have been used to produce compact and versatile fiber based optical cavities [1] and micro-photoluminiscence set-ups [2]. Moreover, these technologies would be also suitable to study N-photon correlations [3], where high collection efficiency and frequency tunability is desirable. In this seminar it will be presented fiber based spectroscopic tools to study single quantum dot optical emission. Fiber Bragg Gratings (FBG) are used to filter the optical emission, enhancing the collection efficiency more than one order of magnitude when compared with conventional monochromator filtering [4]. This enhancement in the collection efficiency is very useful to study single nanostructures with optical emission at telecomm wavelengths (1300 - 1550 nm). Following this strategy we studied time resolved micro-photoluminescence, and hence carrier dynamics in the QD [4]. At the same time, FBG are used in intensity interferometry experiments, to build an all-fiber optics Hanbury Brown and Twiss photon correlator. It is demonstrated ideal single photon emission of a single quantum dot emitting at 1300 nm, using a Fiber Bragg Grating for wavelength filtering and InGaAs Avalanche Photodiodes operated in Geiger mode for single photon detection [5]. This all-optical fiber scheme opens the door to new first and second order interferometers to study photon indistinguishability, entangled photon and photon cross correlation in the more interesting telecom wavelengths. Finally, we have proposed the use of Multicore Fibers (MCF) in conventional spectrometric setups for the characterization and manipulation of single QD emission [6], showing in a series of proof-of-concept experiments the possibilities offered by these fibers in micro-photoluminescence analysis. 

[1] J. Miguel Sánchez et al “Cavity quantum electrodynamics with charge-controlled quantum dots coupled to a fiber Fabry–Perot cavity” New. J. Phys. 15, 045002 (2013).

[2] Lee, C.-M. et al. “Efficient single photon source based on μ-fibre-coupled tunable microcavity”. Sci. Rep. 5, 14309 (2015).

[3] Gonzalez-Tudela, A., Laussy, F. P., Tejedor, C., Hartmann, M. J., del Valle, E. “Two-photon spectra of quantum emitters”. New J. Phys. 15, 033036 (2013).

[4] G. Muñoz Matutano et al. “Time resolved emission at 1.3 micrometers of a single InAs quantum dot by using a tunable fiber bragg grating”. Nanotechnology 25, 35204 (2014).

[5] G. Muñoz-Matutano et al. “1300 nm Ideal Single Photon emission of InAs Quantum Dot by All-Optical Fiber Intensity Interferometry”. Under Review.

[6] G. Muñoz-Matutano et al.  “Parallel Recording of Single Quantum Dot Optical Emission Using Multicore Fibers”. Under Review.