Generation of entangled photon pairs from a silicon bichromatic photonic crystal cavity
Sprache des Titels:
Englisch
Original Kurzfassung:
Integrated quantum photonics leverages the on-chip generation of nonclassical states of light to realize key functionalities of quantum devices.
Typically, the generation of such nonclassical states relies on whispering gallery mode resonators, such as integrated optical micro-rings,
which enhance the efficiency of the underlying spontaneous nonlinear processes. While these kinds of resonators excel in maximizing either
the temporal confinement or the spatial overlap between different resonant modes, they are usually associated with large mode volumes,
imposing an intrinsic limitation on the efficiency and footprint of the device. Here, we engineer a source of time-energy entangled photon
pairs based on a silicon photonic crystal cavity, implemented in a fully CMOS-compatible platform. In this device, resonantly enhanced
spontaneous four-wave mixing converts pump photon pairs into signal/idler photon pairs under the energy-conserving condition in the
telecommunication C-band. The design of the resonator is based on an effective bichromatic confinement potential, allowing it to achieve up
to nine close-to-equally spaced modes in frequency, while preserving small mode volumes, and the whole chip, including grating couplers and
access waveguides, is fabricated in a single run on a silicon-on-insulator platform. Besides demonstrating efficient photon pair generation, we
also implement a Franson-type interference experiment, demonstrating entanglement between signal and idler photons with a Bell inequality
violation exceeding five standard deviations. The high generation efficiency combined with the small device footprint in a CMOS-compatible
integrated structure opens a pathway toward the implementation of compact quantum light sources in all-silicon photonic platforms.
Forschungs-