Optical Module Natural Emission Lightwave-Blocking Filter
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Solution Overview
Problem
In wavelength division multiplexing optical communication systems, interference occurs due to natural emission lightwaves emitted by semiconductor lasers, which have different wavelengths and cannot be blocked by conventional WDMs, leading to crosstalk between signal lightwaves and noise lightwaves.
Innovation Solution
An optical module is introduced that includes a natural emission lightwave-blocking filter placed between the semiconductor laser and the optical fiber, which transmits only the laser oscillation lightwave and blocks the natural emission lightwaves, preventing interference by using a dielectric multilayer film filter with a specific transmittance spectrum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wavelength division multiplexing is used to transmit multiple signals through a single optical fiber, then the signal transmission capacity is improved, but interference and crosstalk occur due to natural emission lightwaves from semiconductor lasers
Solution Approach 1:
The patent extracts and removes the harmful natural emission lightwaves from the optical signal using a dedicated filter component. The filter is specifically designed to block natural emission lightwaves while transmitting the signal lightwave, thereby eliminating the source of interference and crosstalk in WDM systems.
Solution Approach 2:
The patent introduces a filter as an intermediary component between the semiconductor laser and the optical fiber. This filter acts as a mediator that selectively transmits the desired signal lightwave while blocking the harmful natural emission lightwaves, preventing interference before it propagates through the optical fiber.
2Adaptability or versatility
If conventional WDMs are used to separate lightwaves of different wavelengths, then multiplexing and demultiplexing functions are achieved, but natural emission lightwaves cannot be blocked leading to noise
Solution Approach 1:
The patent segments the optical filtering function into two distinct parts: the conventional WDM handles multiplexing and demultiplexing of signal lightwaves, while a dedicated natural emission lightwave filter handles the blocking of natural emission lightwaves. This segmentation allows each component to perform its specific function effectively without interference.
Solution Approach 2:
The patent introduces a natural emission lightwave filter as an intermediary component that works in conjunction with the conventional WDM. This additional filter acts as a mediator that specifically targets and blocks natural emission lightwaves before they can enter the receiver, eliminating noise while preserving the WDM's multiplexing and demultiplexing capabilities.
3Productivity
If semiconductor lasers with different oscillation wavelengths are used for WDM, then multiple signals can be transmitted in parallel, but natural emission lightwaves cause interference between different nodes
Solution Approach 1:
The patent extracts and removes the harmful natural emission lightwaves from each semiconductor laser output using individual filters. By taking out these interfering components before they enter the optical fiber, the system maintains high signal quality and reliability while preserving the ability to transmit multiple signals in parallel through WDM.
Solution Approach 2:
The patent applies preliminary action by blocking natural emission lightwaves at the source (at each semiconductor laser output) before they can propagate through the optical fiber and cause interference at other nodes. This preliminary filtering ensures that only clean signal lightwaves are transmitted, maintaining signal quality throughout the WDM 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
The solution effectively suppresses crosstalk between different signal systems by removing natural emission lightwaves before they enter the optical fiber, ensuring that only the intended signal lightwaves are transmitted, thereby improving the reliability of wavelength division multiplexing optical communication systems.
Implementation Method 1
a natural emission lightwave-blocking filter which blocks the natural emission lightwave and transmits the laser oscillation lightwave
Data Source
AI summary
The inventor found that the lightwave of a semiconductor laser includes, in addition to the laser oscillation lightwave, a weak, continuous noise component having a different wavelength (here, referred to as natural emission lightwave). The inventor also found that in the wavelength division multiplexing communication optical system in which signal lightwaves having a plurality of wavelengths are combined to transmit over a single optical fiber so as to be separated at the other end to receive with a plurality of light-receiving devices, the natural emission lightwave causes crosstalk. A natural emission lightwave-blocking filter that reflects a natural emission lightwave is placed on the optical path between the semiconductor laser and the optical fiber. The natural emission lightwave-blocking filter blocks the natural emission lightwave, preventing the crosstalk.