Shared-Laser Optical Transceiver for Low-Noise Coherent Reception
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Solution Overview
Problem
Conventional optical transmission technologies, particularly coherent optical transmission, face limitations in data center networks due to high costs, phase noise, and complexity, which restrict their application in short-distance ultra-large-bandwidth optical signal transmission.
Innovation Solution
An optical transceiver system utilizing a shared laser as both local oscillator and signal light sources, combined with polarization-maintaining optical waveguides and semiconductor optical amplifier-polarization controllers, implements bi-directional coherent light transmission with reduced phase noise and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate independent light sources are used for local oscillator light and signal light in conventional coherent optical transmission, then the system achieves long transmission distance and large bandwidth, but the cost of optical components increases significantly
Solution Approach 1:
The patent merges the local oscillator light source and signal light source into a single shared laser, eliminating the need for two separate independent light sources. This reduces component costs while maintaining the coherent detection functionality that enables long transmission distances and large bandwidth.
Solution Approach 2:
The shared laser serves multiple functions by providing both local oscillator light for coherent detection and signal light for data transmission. This multi-functional approach reduces the total number of components needed while preserving the system's transmission performance.
2Reliability
If separate independent light sources are used for local oscillator light and signal light, then coherent detection can be performed, but phase noise increases and signal processing complexity increases
Solution Approach 1:
By combining the local oscillator and signal light from a single laser source, the patent eliminates phase noise between independent sources. This reduces the complexity of signal processing required to compensate for phase variations, while maintaining coherent detection capability.
3Reliability
If conventional coherent optical transmission is implemented with separate light sources, then long transmission distance is achieved, but module power consumption increases
Solution Approach 1:
The patent reduces module power consumption by merging the local oscillator and signal light sources into a single laser. This eliminates the energy consumption of maintaining two separate light sources while preserving the long transmission distance capability through coherent detection.
4Stability of the object's composition
If polarization-maintaining optical waveguides are used to transmit local oscillator light, then polarization state stability is improved, but device complexity increases
Solution Approach 1:
The patent applies polarization-maintaining optical waveguides specifically to the local oscillator light path where polarization stability is critical for coherent detection. This targeted application maintains polarization state where needed without unnecessarily complicating the entire optical system.
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 costs and phase noise, ensuring stable data transmission by maintaining polarization states, thus enhancing the applicability of coherent optical transmission in data center networks.
Implementation Method 1
the polarization-maintaining optical waveguide is configured to connect the optical interface and the optical receiver, where a polarization state of the local oscillator light remains unchanged when being transmitted in the polarization-maintaining optical waveguide
Implementation Method 2
the mixer is configured to: receive the local oscillator light from the optical interface, receive signal light modulated on laser light emitted by the laser outside the transceiver, and mix the local oscillator light and the signal light
Implementation Method 3
the optical-to-electrical converter is configured to perform optical-to-electrical conversion on the mixed light to obtain an analog electrical signal that carries data
Data Source
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AI summary
Embodiments of the present invention provide an optical transceiver and an optical coherent receiving system. The optical transceiver includes an optical interface, an optical receiver, and a polarization-maintaining optical waveguide, where the optical receiver includes a mixer, an optical-to-electrical converter, and a digital signal processor. The optical interface is configured to receive first local oscillator light from a first laser outside the transceiver; the mixer is configured to receive the first local oscillator light from the optical interface and receive first signal light modulated on laser light emitted by the laser outside the transceiver; the polarization-maintaining optical waveguide is configured to connect the optical interface and the optical receiver, where a polarization state of the first local oscillator light remains unchanged when being transmitted in the polarization-maintaining optical waveguide; the optical-to-electrical converter and an analog-to-digital converter are configured to perform optical-to-electrical conversion and analog-to-digital conversion on the mixed light to obtain a digital signal that carries data; and the digital signal processor is configured to process the digital signal to obtain the data. The solution in the embodiments of the present invention can reduce costs and phase noise.