SENKO’s Grade-Q Connectors

Quantum computers are anticipated to solve mathematical problems that conventional computers which use binary digits cannot address. While this advanced problem-solving capability offers computational power far exceeding classical computing, it also poses significant threats to cyber security and challenges the foundations of modern cryptography.

Quantum Key Distribution (QKD) is a method that ensures secure encryption and authentication, even in the face of the immense computational power introduced by quantum information technologies. QKD facilitates the exchange of secret symmetric keys for encryption and authentication, maintaining their security against eavesdropping attempts powered by quantum computing. SENKO is developing an optical approach to quantum computing with a range of Ultra Low-Loss connectors designed specifically for Quantum Networking applications.

 

Quantum Key Distribution (QKD)

Quantum Key Distribution (QKD) leverages the quantum properties of photons to securely generate and share symmetric cryptographic keys for use in encryption methods like OTP, HMAC, and AES. It uses protocols such as BB84 (single-photon measurements) and E91 (entangled photons) to detect potential eavesdropping and ensure secure communication. However, integrating QKD into existing networks poses challenges, including the need for specialized infrastructure, point-to-point links, and ultra-low-loss quantum channels.

Quantum Grade Connectors

The Classical Channel handles data exchange between QKD modules, while the Quantum Channel transmits quantum signals like single or entangled photons to derive cryptographic keys. The burgeoning field of quantum communications is anticipated to drive the need for a new generation of optical cables and connectors with lower loss, enabling a higher proportion of single or entangled photons to travel through optical networks without experiencing decoherence, thereby enhancing the efficiency of the quantum optical network. SENKO has engineered an innovative grade of connector that exceeds the highest IEC connector standards. The “Grade-Q” Quantum Connector by SENKO demonstrates insertion losses comparable to those found in fusion splices.

Materiale

For optimal connector quality in quantum networks, it is crucial to focus on the optical fiber’s core and cladding dimensions. Light travels only through the fiber’s core, making its relative size to the cladding significant. Key parameters to control include core-cladding concentricity, core ovality, and cladding ovality. Core-cladding concentricity measures how centrally the core is positioned within the cladding. Minimizing this error is essential for producing Quantum Connectors. Core and cladding ovality refer to their deviation from a perfect circle, affecting connection quality and increasing insertion loss and back reflection.

The ferrule in an optical connector holds the optical fiber in place and aligns with another ferrule to create a continuous light pathway. Concentricity measures the centrality of the ferrule hole relative to its circumference, which is vital for reducing fiber core misalignment. Minimizing the ferrule hole diameter is crucial since a larger hole causes higher fiber position variability. For Single Mode optical fibers of 125μm diameter, the ferrule hole must be as close to this diameter as possible, while allowing space for epoxy adhesive.

Manufacturing

Even with high-quality optical fiber and ferrule components with tight tolerances, the connector manufacturing processes must also be tightly controlled to produce high-quality connectors. One critical process involves the mixing and curing of epoxy. This involves multiple controlled steps to ensure proper management, application, and curing.

Improvements in the ferrule polishing process require precise adjustments to several factors. These include the polishing pad, applied pressure, type of polishing film, polishing angle accuracy, and the polishing apex of curvature. These adjustments control the granularity and smoothness of the connector end-face, reduce the apex offset, and centralize the apex of curvature. These improvements minimize the air gap between the optical fiber cores in the connectors. To further improve the connector performance, the connector is tuned while measuring the optical signal to determine the optimal fiber and ferrule position in the connector.

SENKO’s QuPC Connector

With advancements in optical fiber, connector ferrules, and manufacturing processes, SENKO has developed the QuPC connector, which boasts superior loss performance compared to a fusion splice. The QuPC connectors feature an insertion loss of less than 0.1dB and an optical return loss exceeding 80dB, surpassing ITU specifications. These connectors are also available in CS and SN form factors for higher density connectivity.

Conclusione

SENKO’s QuPC connector sets a new standard in the industry by providing ultra-low-loss performance and precision alignment critical for quantum communication networks. By addressing the unique challenges of Quantum Key Distribution (QKD) and other quantum technologies, the QuPC connector plays a pivotal role in enabling reliable, high-integrity connections, bridging the gap between cutting-edge quantum science and real-world applications.