Ultracompact quantum splitter of degenerate photon pairs

TL;DR

This paper presents an ultra-compact integrated quantum splitter for degenerate photon pairs, utilizing a monolithic chip with a micro-ring resonator and Sagnac loop to generate and split indistinguishable photons efficiently, advancing quantum photonic integration.

Contribution

The work introduces a novel, highly miniaturized quantum splitter device that combines a micro-ring resonator and Sagnac loop on a single chip for deterministic photon pair splitting.

Findings

Achieved a HOM dip visibility of 94.5% indicating high-quality photon indistinguishability.

Demonstrated a footprint of only 0.011 mm² for the integrated quantum splitter.

Enabled efficient generation and splitting of degenerate photon pairs on a monolithic platform.

Abstract

Integrated sources of indistinguishable photons have attracted a lot of attention because of their applications in quantum communication and optical quantum computing. Here, we demonstrate an ultra-compact quantum splitter for degenerate single photons based on a monolithic chip incorporating Sagnac loop and a micro-ring resonator with a footprint of 0.011 mm2, generating and deterministically splitting indistinguishable photon pairs using time-reversed Hong-Ou-Mandel interference. The ring resonator provides enhanced photon generation rate, and the Sagnac loop ensures the photons travel through equal path lengths and interfere with the correct phase to enable the reversed HOM effect to take place. In the experiment, we observed a HOM dip visibility of 94.5 +- 3.3 %, indicating the photons generated by the degenerate single photon source are in a suitable state for further integration with other components for quantum applications, such as controlled-NOT gates.