Abstract
The generation of nonclassical states of light in miniature chips is a crucial step toward practical implementations of future quantum technologies. Semiconductor materials are ideal for achieving extremely compact and massively parallel systems and several platforms are currently under development. In this context, spontaneous parametric downconversion in AlGaAs devices combines the advantages of room temperature operation, possibility of electrical injection, and emission in the telecom band. Here we report on a chip-based AlGaAs source, producing indistinguishable and energy-time entangled photons with a brightness of 7.2×106 pairs/s and a signal-to-noise ratio of 141±12. Indistinguishability between the photons is demonstrated via a Hong–Ou–Mandel experiment with a visibility of 89±3%, mainly limited by the reflectivity of the chip facets, while energy-time entanglement is tested via a Franson interferometer leading to a visibility of 96±4.
Highlights
The ability of our device to produce indistinguishable photons is tested through a HongOu-Mandel (HOM) experiment [27]; in this type of measurement, two indistinguishable photons enter a 50/50 beam splitter at the same time
Light emerging from the opposite end is collected with a second microscope objective, a fiber coupler and filtered with a tunable fibered Bragg grating (FBG) having a full width at half maximum (FWHM) of 10.8 nm
The dependence of the coincidence to accidental ratio (CAR) on both the pump wavelength and the internal pump power has been studied: a maximum value of the CAR of 141 ± 12 is obtained for a pump wavelength around 783 nm and an internal pump power around 625 μW, leading to a brightness of 7.2 × 106 pairs/s
Summary
The ability of our device to produce indistinguishable photons is tested through a HongOu-Mandel (HOM) experiment [27]; in this type of measurement, two indistinguishable photons enter a 50/50 beam splitter at the same time. We report on a chip-based AlGaAs source, producing indistinguishable and energy-time entangled photons with a brightness of 7.2 × 106 pairs/s and a signal-to-noise ratio of 141 ± 12.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
