Quantum Optics Jena GmbH is a Jena, Germany-based company that develops quantum key distribution (QKD) systems for quantum-safe communication. It was founded in 2020 as a spin-off from the Fraunhofer Institute for Applied Optics and Precision Engineering (IOF). Its ELVIS product line uses entanglement-based QKD, in which entangled photon pairs generate a shared secret key that is used to encrypt and decrypt data, and multiple users can communicate securely at the same time using the generated keys.

The company offers hardware, software and services for customers with high security requirements, including government networks, banks, telecommunications operators and critical infrastructure. Its offerings include multi-QKD integration, QKD certification and quantum readiness services. In 2024 it announced a strategic partnership with the IT services provider dacoso and joined an ecosystem for quantum-safe communication launched by ID Quantique. In 2025 Swisscom tested the transmission of keys for symmetric encryption with its system, and the company announced QSyncNextG, a quantum synchronization technology for 5G and 6G networks. The company is also involved in the construction of the European Quantum Communication Infrastructure (EuroQCI).

In 2025 an entangled photon-pair source developed by the company received independent certification from INRiM in Italy, and in 2026 the ELVIS system passed six side-channel security tests under ISO/IEC 23837 conducted by TÜV Informationstechnik. The company won the ATHENE Startup Award UP23@it-sa in 2023 and the Vorsprung economic award in 2026. It raised a seed round in 2021 and an €8.5M Series A led by Join Capital in September 2024. Its activity extends beyond Germany to Singapore, Spain, Austria, Slovakia and the United States, where it has a sales office in North Carolina.