9~GHz measurement of squeezed light by interfacing silicon photonics and integrated electronics

TL;DR

This paper demonstrates a fully integrated silicon photonics and electronics platform capable of high-speed homodyne detection of quantum squeezed light, advancing miniaturized quantum devices and scalable quantum technology.

Contribution

It introduces a CMOS-compatible integrated photonic-electronic device achieving GHz bandwidths for quantum light detection, enabling faster and more compact quantum sensors and communication nodes.

Findings

Achieved 1.7 GHz bandwidth in homodyne detection

Demonstrated shot-noise limited performance beyond 9 GHz

Miniaturized the detection footprint to 0.84 mm

Abstract

Photonic quantum technology can be enhanced by monolithic fabrication of both the underpinning quantum hardware and the corresponding electronics for classical readout and control. Together, this enables miniaturisation and mass-manufacture of small quantum devices---such as quantum communication nodes, quantum sensors and sources of randomness---and promises the precision and scale of fabrication required to assemble useful quantum computers. Here we combine CMOS compatible silicon and germanium-on-silicon nano-photonics with silicon-germanium integrated amplification electronics to improve performance of on-chip homodyne detection of quantum light. We observe a 3 dB bandwidth of 1.7 GHz, shot-noise limited performance beyond 9 GHz and minaturise the required footprint to 0.84 mm. We use the device to observe quantum squeezed light, from 100 MHz to 9 GHz, generated in a lithium niobate waveguide. This demonstrates that an all-integrated approach yields faster homodyne detectors for quantum technology than has been achieved to-date and opens the way to full-stack integration of photonic quantum devices.