Application · Quantum Experiments & QKD
Detectors for quantum experiments, QKD & quantum communication
Quantum optics labs, QKD testbeds, and TCSPC experiments require reliable single-photon detection in the near-infrared and telecom bands. Detector limits directly affect key rate, distance, noise tolerance, system cost, and field deployability. With GeQD LabOne we address these requirements — targeting room-temperature operation, fiber-coupled, and plug-and-play.
The current bottleneck
Telecom-relevant single-photon detection is most often served by InGaAs/InP SPADs or SNSPDs today. InGaAs/InP can be expensive and operationally constrained. SNSPDs can offer excellent performance but require cryogenic infrastructure. This limits deployment where cost, size, power, and field robustness matter.
InGaAs/InP SPAD
SNSPD
Si SPAD
Prototype · Quantum Experiments
Single-photon detector for QKD and quantum experiments
GeQD LabOne
4-Channel SWIR SPAD Module
A compact single-photon detection module for quantum research and industrial prototyping.
Easy handling (Plug-and-Play)
Weight & size efficient
Integration into customer-specific applications
4-channel SWIR SPAD
Fiber-coupled, room-temperature target
Why detector performance matters in QKD
Secure key rate
Detection efficiency directly sets how many sifted bits become secret key bits per second. Every percentage point of efficiency translates into measurable key rate.
Link distance
Dark counts and afterpulsing limit the maximum tolerable channel loss, and therefore the achievable QKD link distance over fibre or free-space.
Clock rate & throughput
Timing jitter and dead time cap the usable clock rate of the QKD system, bounding throughput at high repetition rates.
Noise tolerance & QBER
Low dark count rate keeps the quantum bit error rate (QBER) below thresholds where secure key distillation is still possible.
Field deployability
Cooling, size, weight, and power define whether a detector can leave the lab — into network nodes, satellite ground stations, or industrial sites.
System cost
Detector technology drives a significant share of total QKD system cost, especially when cryogenic infrastructure is required.
GeQD's contribution
A germanium-on-silicon SPAD platform targeting scalable SWIR single-photon detection without cryogenic cooling.
GeQD is developing a Ge-on-Si SPAD platform intended to open a path toward scalable SWIR-capable single-photon detection at or near room temperature, without cryogenic infrastructure — designed for future field-deployable QKD and quantum communication systems.
Discuss detector requirements for quantum experiments & QKD with GeQD.
We engage with system integrators, research groups, and network operators on detector specifications for current and future QKD deployments.
Universität Stuttgart – Institut für Halbleitertechnik
Contact
Pfaffenwaldring 47
70569 Stuttgart, Deutschland
Tel: +49 711 68560896
info@geqd.de
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