High quantum-efficiency photon-number-resolving detector for photonic on-chip information processing

TL;DR

This paper demonstrates a high-efficiency, photon-number-resolving detector integrated into a photonic circuit with over 79% efficiency, enabling advanced quantum optical information processing on-chip.

Contribution

It introduces a novel integrated photonic system with multiplexed detectors achieving high efficiency and photon-number resolution at telecom wavelengths.

Findings

Achieved 79% detection efficiency with multiplexed detectors.

Demonstrated no significant loss due to scattering or reflections.

Enabled placement of number-resolving detectors at arbitrary circuit locations.

Abstract

The integrated optical circuit is a promising architecture for the realization of complex quantum optical states and information networks. One element that is required for many of these applications is a high-efficiency photon detector capable of photon-number discrimination. We present an integrated photonic system in the telecom band at 1550 nm based on UV-written silica-on-silicon waveguides and modified transition-edge sensors capable of number resolution and over 40% efficiency. Exploiting the mode transmission failure of these devices, we multiplex three detectors in series to demonstrate a combined 79% +/- 2% detection efficiency with a single pass, and 88% +/- 3% at the operating wavelength of an on-chip terminal reflection grating. Furthermore, our optical measurements clearly demonstrate no significant unexplained loss in this system due to scattering or reflections. This waveguide and detector design therefore allows the placement of number-resolving single-photon detectors of predictable efficiency at arbitrary locations within a photonic circuit - a capability that offers great potential for many quantum optical applications.