Optical Transceivers Using Bandlimited Duobinary Modulation
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Solution Overview
Problem
Current 40Gb/s optical transceivers based on direct detection methods face limitations in dispersion tolerance, polarization mode dispersion, and cost, making them unsuitable for dynamic reconfiguration in ROADM-based optical networks, and are challenging to fit into smaller form factors like the CFP MSA module.
Innovation Solution
The use of 2x20Gb/s bandlimited-optical duobinary modulation with 10Gb/s optical modulators achieves 40, 50, and 100 Gb/s transmission rates, offering a cost-effective solution with comparable performance to DQPSK, and utilizing 10Gb/s tunable Transmitter Optical SubAssemblies to fit all opto-electronic components within CFP transceiver modules.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If 40Gb/s direct detection methods with complex modulation formats (DQPSK, DPSK) are used, then transmission performance improves, but device complexity and cost increase
Solution Approach 1:
The patent segments the high-speed signal into multiple lower-speed lanes (e.g., four 10Gb/s lanes for 40Gb/s transmission). Each lane uses simple NRZ modulation instead of complex formats, reducing per-lane complexity while achieving aggregate high-speed transmission through parallel processing and multiplexing.
2Length of stationary object
If thermally-tuned phase demodulators and optical dispersion compensators are used, then transmission distance improves, but traffic recovery time increases
Solution Approach 1:
The patent replaces thermal tuning mechanisms with electrically-tuned components. Electrically-tuned phase demodulators and dispersion compensators enable fast reconfiguration in the microsecond range, supporting dynamic ROADM networks while maintaining long-haul transmission capabilities.
3Productivity
If multiple opto-electronic components are integrated into 300pin modules, then transmission capacity increases, but packaging difficulty increases
Solution Approach 1:
The patent employs nested packaging where smaller form-factor pluggable modules (FFPMs) are integrated within the 300pin module structure. Each FFPM contains a subset of opto-electronic components (lasers, modulators, detectors), and multiple FFPMs are combined to achieve the required transmission capacity, simplifying the overall packaging process.
4Volume of moving object
If CFP MSA module form factor is used, then space efficiency improves, but component integration challenge increases
Solution Approach 1:
The patent integrates multiple smaller FFPMs within the compact CFP module form factor. This nested approach allows efficient space utilization while managing component integration complexity through modular design, enabling high-capacity transmission in a space-efficient package.
Data Source
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AI summary
Disclosed by way of exemplary embodiments, a 40/50/100Gb/s Optical Transceivers/transponders which use opto-electronic components at data rates collectively that are lower than or equal to half the data rate, using two optical duobinary carriers. More specifically, the exemplary embodiments of the disclosed optical transceivers/transponders relate to a 43Gb/s 300pin MSA and a 43~56Gb/s CFP MSA module, both include a two-carrier optical transceiver and the appropriate hardware architecture and MSA standard interfaces. The two-carrier optical transceiver is composed of a pair of 10Gb/s optical transmitters, each using band-limited duobinary modulation at 20~28Gb/s. The wavelength channel spacing can be as little as 19~25GHz. The same principle is applied to a 100Gb/s CFP module, which is composed of four tunable 10Gb/s optical transmitters, with the channel spacing between optical carriers up to a few nanometers.