Coherent Optical Receiver Parallel Signal Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-bandwidth optical transmission systems face challenges in low-cost interconnection between electro-optical and electronic ICs due to different thermal characteristics and the need for expensive impedance-matching and power-driver circuits, which increase cost and noise, especially at high bit rates and complex signal processing.
Innovation Solution
A coherent optical receiver module with a single optical hybrid and an analog frequency decimator generates parallel analog signals from high-bandwidth optical channel light, which are then processed by an electronic signal processing IC with A/D converters and a DSP to reconstruct the signal, reducing the need for high-bandwidth transmission lines and allowing for easier, less expensive implementation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If high-bandwidth transmission lines are used to interconnect electro-optical and electronic ICs, then signal transmission capability is improved, but cost and complexity increase due to expensive impedance-matching and power-driver circuits
Solution Approach 1:
The patent divides the high-bandwidth analog signal into multiple parallel lower-frequency signal streams using an analog frequency decimator. This segmentation allows each signal stream to be transmitted over separate lower-bandwidth channels, eliminating the need for expensive high-bandwidth transmission lines and associated impedance-matching circuits while maintaining overall signal integrity through subsequent digital signal processing reconstruction
Solution Approach 2:
The patent introduces an analog frequency decimator as an intermediary device between the electro-optical IC and electronic IC. This decimator converts a single high-bandwidth analog signal into multiple lower-frequency parallel signals, serving as a mediator that enables cost-effective interconnection by translating the signal into a form suitable for lower-cost transmission media
2Reliability
If impedance-matching and power-driver circuits are added to ensure signal integrity, then transmission reliability is improved, but cost and noise increase
Solution Approach 1:
The patent replaces the traditional analog approach requiring impedance-matching circuits and power-driver stages with a digital signal processing-based solution. By converting the analog signal to digital samples and performing reconstruction in the digital domain, the system eliminates the need for complex analog circuitry that generates noise and increases cost, while maintaining or improving signal transmission reliability
3Adaptability or versatility
If electro-optical and electronic ICs are interconnected directly, then device integration is improved, but thermal compatibility problems arise due to different thermal characteristics
Solution Approach 1:
The patent segments the signal processing functions across separate electro-optical and electronic ICs, connected through the frequency decimation interface. This physical separation allows each IC to be optimized for its specific function and thermal requirements, with the electro-optical IC operating at its optimal temperature and the electronic IC (containing the decimator and DSP) managing its own thermal characteristics independently, thus resolving thermal compatibility issues while maintaining functional integration
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 enables low-cost interconnection between electro-optical and electronic ICs by dividing analog signal processing into multiple parallel lower-frequency signals, reducing noise and cost while maintaining high-bandwidth performance.
Implementation Method 1
a single optical hybrid for mixing the optical channel light with a corresponding continuous wave local oscillator light to generate a mixed light containing the high-bandwidth data signal
Implementation Method 2
at least one photodetector
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 3
AI summary
A coherent optical receiver includes an electro-optic module coupled to an electronic signal processing Integrated circuit (IC) via a parallel analog transmission line bus. The electro-optic module 54 receives and detects an optical channel light including a high-bandwidth signal modulated thereon. The electro-optic module 54 includes: a single optical hybrid 22 for mixing the optical channel light with a corresponding continuous wave local oscillator light to generate a mixed light containing the high-bandwidth data signal, at least one photodetector 24; and an analog frequency decimator 62 for generating a set of parallel analog signals, each analog signal representing a respective portion of the high-bandwidth signal. The electronic signal processing IC 58 includes a respective Analog-to-digital (A/D) converter 64 for sampling each one of the set of parallel analog signals, and for generating corresponding parallel digital sample streams; and a digital signal processor (DSP) 28 for processing the parallel digital sample streams to extract the high-bandwidth signal.