Optical Communication Device Wavelength Control
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Solution Overview
Problem
Existing optical communication systems face challenges in maintaining accurate wavelength intervals for wavelength-multiplexed optical signals due to temperature and time-related changes in transmission wavelength variable filters, leading to spectral overlap and degraded transmission quality.
Innovation Solution
An optical communication device comprising light output units, a multiplexing unit, a reference light output unit, a wavelength generation unit, and a wavelength control unit that compares and adjusts the wavelength of optical signals based on interference components to maintain precise wavelength intervals, using a reference light and optical comb generation to ensure accurate wavelength alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the wavelength interval of wavelength-multiplexed optical signals is narrowed to improve frequency utilization efficiency, then transmission capacity increases, but spectral overlap between adjacent channels increases causing deterioration of transmission quality
Solution Approach 1:
The patent changes the parameter of wavelength interval from a fixed narrow value to a dynamically adjustable value. The wavelength interval control unit varies the wavelength interval based on transmission distance and other conditions, allowing optimization between frequency utilization (narrow interval) and transmission quality (sufficient separation). This resolves the contradiction by making the interval adaptive rather than static.
2Measurement precision
If a transmission wavelength variable filter is used to control the wavelength of optical signals, then wavelength alignment with reference signal is achieved, but the filter characteristics change with temperature and time causing wavelength shift and spectral overlap
Solution Approach 1:
The patent implements a feedback mechanism where the wavelength interval is measured by comparing with a reference optical signal, and the wavelength interval control unit adjusts the wavelength based on this measurement. This closed-loop feedback compensates for temperature and time-induced drift in the variable filter characteristics, maintaining stable wavelength alignment without requiring the filter itself to be stable.
Solution Approach 2:
The patent introduces a reference optical signal as an intermediary standard. Instead of directly controlling the absolute wavelength of each channel (which is sensitive to filter drift), the system controls the relative wavelength interval with respect to the reference signal. This intermediary reference provides a stable basis for wavelength control that is independent of the variable filter's absolute characteristics.
3Measurement precision
If indirect wavelength control using transmission wavelength variable filter is employed, then wavelength coincidence with reference signal is achieved, but control accuracy depends on filter accuracy which degrades with environmental changes
Solution Approach 1:
The system continuously measures the actual wavelength interval by comparing optical signals with a reference signal and feeds this information back to the wavelength interval control unit. This feedback loop compensates for environmental variations in real-time, maintaining control accuracy independent of filter characteristics degradation.
Solution Approach 2:
The patent replaces direct mechanical/optical control of absolute wavelength (which depends on filter physical characteristics) with control of relative wavelength interval through optical comparison and feedback. This substitution of control methodology eliminates dependence on the mechanical stability of the variable filter itself.
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
The solution enables the output of wavelength-multiplexed optical signals with higher accuracy, reducing spectral overlap and improving transmission quality by directly controlling the wavelength of optical signals to match the intended interval, thus enhancing the overall performance of the optical communication system.
Implementation Method 1
frequency-modulating a predetermined light source with an output from a microwave oscillator
Implementation Method 2
controlling, depending on an interference component between the wavelength-multiplexed signal and a light having at least one wavelength among the plurality of lights
Data Source
AI summary
[Problem] To provide an optical communication device and the like with which the optical signals output by multiple light output units can be set with an accurate wavelength interval.[Solution] An optical communication device equipped with: multiple light output units that output optical signals of mutually different wavelengths; a multiplexing unit that outputs a wavelength-multiplexed signal by multiplexing the multiple optical signals output from the multiple light output units; a reference light output unit that outputs reference light serving as a reference; a wavelength generation unit that, on the basis of the reference light, outputs multiple light beams having a wavelength interval in accordance with a prescribed frequency; and a wavelength control unit that controls the wavelength of the optical signals output by the light output units in accordance with the interference component between the wavelength-multiplexed signal and light with the wavelength of at least one of the multiple light beams.