Fiber Link Laser Shutoff Using Counter-Propagating Cut Detection
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Solution Overview
Problem
Conventional fiber optic systems with optical amplifiers struggle to detect fiber cuts quickly enough in low latency, high transmission power scenarios, such as those using Hollow Core Fiber, due to the interruption of copropagating Optical Service Channel signals being too slow for automatic laser shutoff.
Innovation Solution
Implementing a detection mechanism that utilizes one or two counter-propagating monitoring signals, such as Optical Service Channel, telemetry, or Optical Time Domain Reflectometer signals, to rapidly detect fiber cuts and trigger automatic laser shutoff or power reduction in less than 100 ms, ensuring faster response times for safety and compliance with class 1M laser safety requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If copropagating Optical Service Channel signals are used for fiber cut detection, then the system can detect fiber interruptions, but the detection speed is too slow for high-power transmission safety requirements
Solution Approach 1:
The patent inverts the conventional copropagating OSC detection approach by using counter-propagating monitoring signals instead. This reversal enables the monitoring signal to travel in the opposite direction of traffic signals, allowing immediate local detection of fiber cuts without waiting for remote signaling, thus achieving the required sub-100ms detection speed for high-power transmission safety
Solution Approach 2:
The patent introduces counter-propagating monitoring signals as intermediaries to detect fiber cuts. These dedicated monitoring signals serve as mediators that continuously probe the fiber integrity and trigger immediate local shutdown when disruptions are detected, resolving the speed limitation of conventional traffic signal-based detection methods
2Power
If high transmission power is used in low latency fibers, then signal quality and transmission distance improve, but the risk of laser safety hazards increases
Solution Approach 1:
The patent implements preliminary action by continuously monitoring fiber integrity with counter-propagating signals before hazardous conditions can develop. When a fiber cut is detected, the system proactively shuts down high-power lasers immediately, preventing safety hazards rather than reacting after they occur. This preemptive approach enables safe operation at high transmission power levels
Solution Approach 2:
The patent establishes a rapid feedback loop where counter-propagating monitoring signals continuously assess fiber integrity and immediately trigger power reduction or shutdown when disruptions are detected. This real-time feedback mechanism ensures that high transmission power is maintained only when safe, automatically reducing power when safety risks are detected, thus resolving the contradiction between power and safety
Data Source
AI summary
Laser safety shutoff or power reduction is disclosed for optically amplified fiber optic links with high transmission power. In an embodiment, a network element includes an amplifier configured to amplify one or more traffic carrying signals that are being transmitted over an optical fiber connected to the network element; a first receiver configured to receive a first monitoring signal that counter propagates over the optical fiber relative to the one or more traffic carrying signals; and circuitry configured to one or more of reduce power of the amplifier and shut off lasers associated with the amplifier, responsive to a loss of signal at the first receiver.