Outstanding performance of broadband pillar microcavity
Extremely efficient entangled photon pair sources can be achieved by employing a simple but effective approach – placing quantum dots in broadband pillar microcavities. - It's a novel device with potential to enhance digital security, says Professor Ana Predojević, head of Quantum Photonics group at Fysikum.
Sources of entangled photons are a key enabler of quantum technology. Such sources can be achieved employing quantum dots, however, ensuring high efficiency with which the photon pairs are channeled from the quantum dot to the collection optics remains a challenge. Meeting this requirement calls for the use of broadband photonic structures that can efficiently extract pairs of photons that have different wavelengths.
"The entangled photons in Quantum technology is very efficient, scalable for fabrication and usable within the field of digital security", says Ana Predojevic, Associate Professor at Fysikum.
Realization of an affordable and scalable photon pair source for quantum technologies
In this paper the researchers demonstrate, using a broadband (low Q-factor) pillar microcavity, that pairs of time-bin entangled photons can be collected using a cavity that enables collection efficiency of ~70%. Such high performance was achieved by pillar microcavity design that features strong suppression of emission into non-cavity modes.
Further optimizations will lead to collection efficiency values >80%. What makes this device exceptional is the outstanding performance combined with an extremely low fabrication complexity. This greatly increases the device fabrication yield and provides a near term route to scalable manufacturing of highly efficient entangled photon pair sources.
Last updated: July 15, 2022
Source: Communications Office