Optical Receiver Polarization Demultiplexing with Minimal Phase Shifters
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Solution Overview
Problem
Current polarization demultiplexing techniques in optical communication systems require complex and costly digital coherent receivers with high power dissipation, especially due to the need for local oscillator lasers and redundant phase shifters, which increase insertion loss and system complexity.
Innovation Solution
An optical receiver design that employs a polarization controller with only two phase shifters per wavelength channel, utilizing forward error correction (FEC) to correct burst errors during phase resets, and encodes a pilot carrier signal to aid in demultiplexing, thereby simplifying the demultiplexing process and reducing insertion losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If digital coherent receivers with local oscillator lasers and redundant phase shifters are used for polarization demultiplexing, then demultiplexing accuracy is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent extracts and removes the local oscillator laser and redundant phase shifters from the receiver architecture. By using a simplified polarization controller with only necessary phase shifters and leveraging FEC for error correction, the system achieves polarization demultiplexing without the complex and power-hungry components of traditional digital coherent receivers.
Solution Approach 2:
The patent replaces expensive, complex components (local oscillator lasers, redundant phase shifters) with simpler, more cost-effective alternatives. The simplified polarization controller uses minimal phase shifters, and FEC provides robust error correction without requiring the removed components, effectively substituting cheap components for expensive ones.
2Reliability
If local oscillator lasers and redundant phase shifters are used in polarization demultiplexing, then demultiplexing performance is improved, but power dissipation increases
Solution Approach 1:
The patent removes the local oscillator laser and redundant phase shifters from the system, directly eliminating their power consumption. The simplified polarization controller with minimal phase shifters and FEC-based error correction maintains demultiplexing performance while dramatically reducing power dissipation compared to traditional digital coherent receivers.
3Measurement precision
If redundant phase shifters are used in the polarization controller, then polarization control accuracy is improved, but insertion loss increases
Solution Approach 1:
The patent extracts and removes redundant phase shifters from the polarization controller architecture. By using only the necessary phase shifters and leveraging FEC for error correction, the system maintains polarization control accuracy while eliminating the insertion losses associated with additional phase shifter components.
4Adaptability or versatility
If digital coherent receivers with multiple phase shifters are used, then polarization demultiplexing capability is improved, but ease of operation deteriorates due to higher complexity
Solution Approach 1:
The patent removes redundant phase shifters and local oscillator lasers, simplifying the system architecture. The remaining polarization controller with minimal phase shifters is easier to operate and control, while FEC provides robust error correction that maintains demultiplexing capability without requiring complex additional components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces system complexity and power consumption while maintaining reliable communication by leveraging FEC to correct errors, enabling efficient polarization demultiplexing without the need for redundant phase shifters and local oscillator lasers.
Implementation Method 1
The PBS is configured to split a received optical signal having an unknown polarization state into two orthogonal polarizations (x'-polarization and y'-polarization)
Implementation Method 2
The method includes phase shifting either the x'-polarization or the y'-polarization according to a first rotation angle
Data Source
AI summary
An example embodiment includes optical receiver that includes a polarization beam splitter (PBS), a polarization controller, and a forward error correction (FEC). The PBS is configured to split a received optical signal having an unknown polarization state into two orthogonal polarizations (x′-polarization and y′-polarization). The polarization controller includes no more than two couplers and no more than two phase shifters per wavelength channel of the x′-polarization and the y′-polarization. The polarization controller is configured to demultiplex the x′-polarization and the y′-polarization into a first demultiplexed signal having an first polarization on which a data signal is modulated and a second demultiplexed signal having a second, orthogonal polarization on which a pilot carrier oscillator signal is encoded. The FEC decoder module is configured to correct a burst of errors resulting from resetting one of the phase shifters based on error correction code (ECC) data encoded in the data signal.