Coherent Optical Mixer Circuit Phase Error Evaluation
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Solution Overview
Problem
The existing coherent optical mixer circuits require a delay circuit for phase error evaluation, which necessitates additional manufacturing steps, increases costs, and reduces chip yield due to the need for cutting away the delay circuit after evaluation.
Innovation Solution
A coherent optical mixer circuit design that incorporates a 4-input-and-4-output MMI circuit, allowing phase error measurement without a delay circuit, enabling evaluation in the wafer status prior to chip cutting by using additional input ports for monitor light and a delay circuit for phase error evaluation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a delay circuit is added for phase error evaluation, then measurement precision is improved, but device complexity increases and manufacturing precision deteriorates due to additional cutting steps
Solution Approach 1:
The coherent optical mixer circuit is designed with additional input ports that allow the same circuit structure to serve dual purposes: normal signal processing and phase error evaluation. By inputting monitor light through these additional ports, the circuit can evaluate phase errors without requiring a separate delay circuit, thus achieving multi-functionality and reducing overall device complexity.
Solution Approach 2:
The invention extracts the phase error evaluation function from the traditional delay circuit structure and integrates it directly into the coherent optical mixer circuit. This eliminates the need for a separate delay circuit component and the associated cutting steps, simplifying the overall device structure while maintaining measurement precision.
2Measurement precision
If a delay circuit is added for phase error evaluation, then measurement precision is improved, but manufacturing time increases due to additional cutting steps
Solution Approach 1:
The invention removes the delay circuit component entirely and extracts its phase error evaluation function into the main coherent optical mixer circuit. This eliminates the additional cutting steps required to remove the delay circuit after evaluation, significantly reducing manufacturing time while maintaining the ability to evaluate phase errors.
Solution Approach 2:
The phase error evaluation capability is built into the circuit structure from the beginning, allowing evaluation to be performed at any stage including during wafer fabrication. This eliminates the need for post-fabrication cutting steps and enables earlier evaluation, reducing overall manufacturing time.
3Measurement precision
If a delay circuit is added for phase error evaluation, then measurement precision is improved, but chip yield decreases due to reduced chip area
Solution Approach 1:
The coherent optical mixer circuit is designed with additional input ports that enable the same chip area to serve dual purposes: normal signal processing and phase error evaluation. By integrating the evaluation function into the existing circuit structure rather than adding a separate delay circuit, the chip area is utilized more efficiently, maintaining higher chip yield while enabling phase error measurement.
Solution Approach 2:
The invention merges the phase error evaluation function with the coherent optical mixer circuit structure. By combining these functions into a single integrated circuit without requiring separate delay circuit components, the overall chip area is reduced, allowing more chips to be produced per wafer and thus increasing chip yield.
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 eliminates the need for cutting away the delay circuit, reducing manufacturing time and cost, and increasing chip yield by allowing phase error evaluation before chip cutting, thus enhancing the efficiency and cost-effectiveness of the manufacturing process.
Implementation Method 1
a 4-input-and-4-output MMI circuit... in which two input ports are used as a coherent optical mixer
Implementation Method 2
The coherent optical mixers 9104 and 9105 are light circuits having 2 inputs and 4 outputs in which the maximum interference is obtained when two inputted light waves have a phase angle difference of 0, 90, 180, and 270 degrees
Data Source
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AI summary
A coherent optical mixer circuit is provided that can measure a phase error without requiring a step of cutting away a delay circuit. Odd-numbered or even-numbered two of four inputs of an 4-input-and-4-output multimode interference circuit are connected to an input mechanism. The four outputs of the multimode interference circuit are all connected to an output mechanism to the exterior. Other two inputs of the multimode interference circuit are connected to two monitor waveguides. One of the monitor waveguide is longer than the other to configure a light delay circuit. The monitor waveguides constituting the light delay circuit are connected to the respective outputs of a 2-branched light splitter. The 2-branched light splitter has an input connected to a monitor light input mechanism from the exterior via a monitor input waveguide.