Integrated balanced homodyne photonic–electronic detector for beyond 20  GHz shot-noise-limited measurements

Abstract

Optical homodyne detection is used in numerous quantum and classical applications that demand high levels of sensitivity. However, performance is typically limited due to the use of bulk optics and discrete receiver electronics. To address these performance issues, in this work we present a co-integrated balanced homodyne detector consisting of a silicon photonics optical front end and a custom integrated transimpedance amplifier designed in a 100 nm GaAs pHEMT technology. The high level of co-design and integration provides enhanced levels of stability, bandwidth, and noise performance. The presented detector shows a linear operation up to 28 dB quantum shot noise clearance and a high degree of common-mode rejection, at the same time achieving a shot-noise-limited bandwidth of more than 20 GHz. The high performance of the developed devices provide enhanced operation to many sensitive quantum applications such as continuous variable quantum key distribution, quantum random number generation, or high-speed quantum tomography.

43-GHz bandwidth real-time amplitude measurement of 5-dB squeezed light using modularized optical parametric amplifier with 5G technology

“…In contrast, broadband balanced detectors lift the bandwidth beyond a GHz or even higher. Recently, GHz homodyne detectors built with silicon photonics technology [21,22] have been demonstrated; one of them measured a broadband squeezed vacuum [21]. Nevertheless, to increase the bandwidth, it is necessary to use photodiodes with a thin active layer and a small photosensitive area, which is not suitable for achieving high detection efficiency.…”

“…To measure quantum light, the detection efficiency of a photodiode must be very high, but a photodiode specifically designed for this purpose will inevitably have a narrow bandwidth. Realistically, the bandwidth is limited to a few hundred MHz [18][19][20] or at best a few GHz with state-of-the-art silicon photonics technology [21,22].…”

Discrete-variable quantum key distribution with homodyne detection

“…We can simplify the summation in Eq. (9). Making use of the Kronecker delta in the summation, we have…”

“…One of the key benefits of CV-QKD is the use of homodyne detectors, which possess appealing features like high quantum efficiency, cost-effectiveness, and room-temperature operation. Moreover, homodyne detectors can be readily integrated into a photonic integrated circuit [6][7][8][9], which holds great promise for monolithic CMOS-compatible fabrication and largescale integrated quantum networks.…”

Discrete-variable quantum key distribution with homodyne detection

“…One of the key benefits of CV-QKD is the use of homodyne detectors, which possess appealing features like high quantum efficiency, cost-effectiveness, and room-temperature operation. Moreover, homodyne detectors can be readily integrated into a photonic integrated circuit [6][7][8][9], which holds great promise for monolithic CMOS-compatible fabrication and large-scale integrated quantum networks.…”