Kien Phan Huy

Photon pair source based on parametric fluorescence in periodically poled twin-hole silica fiber

We present observations of quasi-phase matched parametric fluorescence in a periodically poled twin-hole silica fiber. The phase matching condition in the fiber enables the generation of a degenerate signal field in the fiber-optic communication band centered on 1556 nm. We performed coincidence measurements and a Hong-Ou-Mandel experiment to validate that the signal arises from photon pairs. A coincidence peak with a signal to noise ratio (SNR) of 4 using 43 mW of pump power and a Hong-Ou-Mandel dip showing 40% net visibility were measured. Moreover, the experiments were performed with standard single mode fibers spliced at both ends of the poled section, which makes this source easy to integrate in fiber-optic quantum communication applications.

Enhanced cross phase modulation instability in birefringent photonic crystal fibers in the anomalous dispersion regime

We study Cross Phase Modulational Instability (CPMI) -a particular form of vector modulational instability- in the anomalous dispersion regime in highly birefringent, strongly dispersive optical fibers. When the pump power is high, the detuning of the Scalar Modulational Instability (SMI) is comparable to the detuning of the CPMI. The gain of the CPMI -which is usually much smaller than the gain of the SMI-, is then strongly enhanced and becomes much larger than the gain of the SMI. This theoretical prediction is well verified experimentally using small core photonic crystal fibers.

Properties and limitations of chalcogenide films

Two chalcogenide films with composition Ge25-Sb10+xS65 (x = 0, 10) and Te20As30Se50, called 2S1G and TAS, respectively, are studied. These materials have high linear and nonlinear refractive indices and present interesting photosensitive behavior toward bandgap light. Further, these chalcogenides glasses can be deposited in an amorphous thin ?lm for optical coatings or waveguides. Their properties and limitations, including their photoinduction effects, nonlinear Kerr effect, photodiffusion of silver, and aging, are discussed.

Fiber optics implementation of single quantum coin tossing

We report an all fiber optics experimental implementation of quantum coin tossing using attenuated laser pulses at 1550 nm in which a single coin is tossed whose randomness is higher than achievable by any classical protocol.

Photon pair source based on periodically poled twin-hole silica fibre

In this paper we report the experimental observation of photon pair generation in periodically poled twin-hole silica fibre. Compared with periodically poled D-shape fibres, twin-hole fibres have important advantages: direct splicing to standard fibres is possible; as well as periodic poling technology compatible with tens of centimetres of interaction length, thus potentially ensuring higher conversion.