On-chip, photon-number-resolving, telecom-band detectors for scalable photonic information processing

TL;DR

This paper presents an integrated, on-chip photon-number-resolving detector operating at telecom wavelengths, capable of resolving up to five photons with potential for scalable quantum photonic applications.

Contribution

It introduces a novel evanescently coupled on-chip detector design that can be positioned arbitrarily within photonic circuits for scalable quantum processing.

Findings

Detects up to 5 photons in the telecom band.

Achieves a detection efficiency of 7.2%.

Demonstrates polarization sensitivity.

Abstract

Integration is currently the only feasible route towards scalable photonic quantum processing devices that are sufficiently complex to be genuinely useful in computing, metrology, and simulation. Embedded on-chip detection will be critical to such devices. We demonstrate an integrated photon-number resolving detector, operating in the telecom band at 1550 nm, employing an evanescently coupled design that allows it to be placed at arbitrary locations within a planar circuit. Up to 5 photons are resolved in the guided optical mode via absorption from the evanescent field into a tungsten transition-edge sensor. The detection efficiency is 7.2 \pm 0.5 %. The polarization sensitivity of the detector is also demonstrated. Detailed modeling of device designs shows a clear and feasible route to reaching high detection efficiencies.