Laser-Based Optical Reference Signal Transmission for Enhanced Quantum Computing Performance

TO-216 • PT 1.3123 • As of 05/2025
Peter Grünberg Institute
Integrated Computing Architectures (PGI-4)

Technology

We introduce a novel method for the optical transmission of user data via laser from a sender to a receiver, specifically designed for systems operating at extremely low temperatures – such as quantum computers near absolute zero. The system uses a laser diode at room temperature to send both reference signals and user data through free-space or optical fiber to a receiver equipped with a photodiode, which operates reliably even at millikelvin temperatures. The reference signals, which can be either symbol-based or frequency-based, are used to precisely define and prepare the quantum bits (Qbits) or quantum dots in the receiver for data transmission. By leveraging optical rather than electrical transmission, the technology enables highly accurate, low-loss, and low-power communication, making it ideal for advanced cryogenic applications where energy efficiency and signal integrity are critical.

Problem addressed

One of the challenges for novel quantum computers that include components at cryogenic temperatures is the data transmission to the cryogenic system. Such data transmission to cryogenic systems is usually carried out via electrical signals transmitted through extensive cable systems. This approach faces significant challenges: electrical reference signals often suffer from distortion and loss, especially over long distances, requiring complex pre-distortion compensation. Low-impedance matching increases power consumption, while high-impedance mismatches introduced signal distortions, both of which could degrade system performance. In the ultra-low temperature environments necessary for quantum computing, even minimal heat generation from high power consumption could disrupt the delicate thermal balance, making it difficult to maintain the required operating temperatures. These issues limit the scalability, efficiency, and practicality of advanced quantum systems, creating a pressing need for a more robust, energy-efficient transmission solution.

Solution

Our approach solves the above problems by replacing traditional electrical transmission with optical data transfer using lasers. By sending both reference and user data optically, the system eliminates the need for power-hungry electrical lines and complex signal compensation. The transmitter, for example operating at room temperature, uses a laser diode to transmit signals directly to a photodiode receiver in the cryogenic environment. This approach drastically reduces power consumption and virtually eliminates heat generation at the receiver, preserving the ultra-low temperatures needed for quantum computing. Furthermore, optical transmission is immune to electromagnetic interference and signal degradation over distance, ensuring high fidelity and reliability. The result is a streamlined solution that enables precise control and efficient data transfer in even the most demanding cryogenic applications, offering clear advantages for next-generation quantum technologies.

Benefits and Potential Use

The potential applications for this technology are relevant particularly for organisations developing or operating quantum computers and other cryogenic systems. It is ideally suited for the transmission of reference and user data to superconducting circuits, quantum dots, and Qbits in quantum computing environments. Beyond quantum computing, the technology can be adapted for any system requiring high-integrity data transfer at low temperatures, such as advanced scientific instrumentation, space-based detectors, and ultra-sensitive measurement devices. Its low power requirements and robust signal integrity make it attractive for scalable, high-performance installations. By licensing this technology, our partners can gain a competitive edge in the rapidly evolving fields of quantum information processing and cryogenic electronics.

Development Status and Next Steps

Forschungszentrum Jülich (FZJ) has extensive expertise in this field and holds several patents. Our technology described above is continuously being enhanced. Our Peter Grünberg Institute (PGI-4) – Integrated Computing Architectures – already cooperates with numerous national and international companies and scientific partners. Forschungszentrum Jülich focuses on energy and cost-efficient devices suitable for application in various emerging technologies. We are thus constantly seeking cooperation partners and/or licensees in this field and adjacent areas of research and applications.

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