Single-Fiber Coherent Optics Using Split Wavelengths for Bidirectional Links
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing single-fiber bidirectional optical transmission technologies using miniaturized single-light-source coherent optical transceivers are limited by the requirement for identical wavelengths in both directions, preventing signal transmission, and existing dual-light-source coherent optical transceivers are not compatible with miniaturized designs.
Innovation Solution
Implementing a single-fiber bidirectional optical transmission apparatus with two miniaturized single-light-source coherent optical transceivers, where the wavelengths of the optical signals are differentiated, allowing for virtual dual-light-source operation, and incorporating a framing chip or self-recovery clock mode to manage clock signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate optical cables are used for upward and downward transmission, then transmission reliability is improved, but installation complexity and cost increase
Solution Approach 1:
The patent combines upward and downward optical transmission into a single optical cable by using different wavelengths for each direction. The wavelength division multiplexing device separates and combines light signals of different wavelengths, allowing bidirectional communication through one cable instead of requiring separate cables for each direction.
Solution Approach 2:
The optical cable is made universal by enabling it to carry multiple wavelength channels simultaneously for bidirectional transmission. The wavelength division device allows the same physical cable to perform multiple functions - transmitting both upward and downward signals through wavelength multiplexing.
2Productivity
If wavelength division multiplexing is implemented, then fiber usage efficiency is improved, but device complexity increases
Solution Approach 1:
The patent segments the optical spectrum into different wavelength channels for separate transmission paths. The wavelength division device separates light into different wavelength bands using optical filters or diff gratings, allowing multiple independent data streams to traverse the same fiber simultaneously.
Solution Approach 2:
The patent adds the wavelength dimension to the traditional single-channel fiber transmission. Instead of using one wavelength per fiber, multiple wavelengths are utilized, effectively transforming a one-dimensional transmission system into a multi-dimensional one where frequency becomes an additional transmission resource.
3Ease of manufacture
If a single optical cable is used for bidirectional transmission, then installation cost is reduced, but signal interference risk increases
Solution Approach 1:
The patent converts the potential harmful effect of signal interference into a beneficial separation mechanism by using wavelength division. Different wavelengths naturally propagate through the optical fiber with minimal cross-interference, and the wavelength division device exploits this physical property to isolate upward and downward signals.
Solution Approach 2:
The wavelength division device acts as an intermediary that separates and manages signals of different wavelengths. It uses optical components such as filters or diff gratings to direct specific wavelength ranges to appropriate transmission paths, preventing signal interference while maintaining efficient fiber utilization.
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
Enables high-rate optical transmission in both directions using miniaturized transceivers, maintaining signal integrity and compatibility with existing dual-fiber systems, while allowing for flexible fiber connections and scalability.
Implementation Method 1
transmitting different wavelengths of light in different directions
Implementation Method 2
the optical receiver 30 to receive the light
Data Source
Figure 1~3
Figure 4~6a
Figure 6b~6d
AI summary
Embodiments of this application provide a single-fiber bidirectional optical transmission apparatus, a wavelength division multiplexing device, and an optical transmission system, to implement single-fiber bidirectional transmission by using miniaturized single-light-source coherent optical transceivers. The single-fiber bidirectional optical transmission apparatus includes: a first single-light-source coherent optical transceiver, configured to: receive a first optical signal from a first multiplexer/demultiplexer, convert the first optical signal into a first electrical signal, and send the first electrical signal to a first client signal processing apparatus; and a second single-light-source coherent optical transceiver, configured to: receive a second electrical signal from the first client signal processing apparatus, convert the second electrical signal into a second optical signal, and send the second optical signal to the first multiplexer/demultiplexer. A wavelength of the second optical signal is different from a wavelength of the first optical signal. The single-fiber bidirectional optical transmission apparatus may be used in a wavelength division multiplexing device.