Silicon Photonics Extinction Ratio Control with Phase Shifters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing silicon photonic circuits face challenges in achieving optimal extinction ratios due to uneven splitting and combining of optical signals, leading to increased fabrication costs, high insertion losses, and wavelength dependence, which can inadvertently activate downstream devices.
Innovation Solution
The use of phase shifters and intensity modulators in silicon photonic elements to actively control the phase and amplitude of split optical signals, compensating for fabrication imperfections and ensuring optimal extinction ratios without inducing high insertion losses or back reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If optical signals are split and combined using conventional silicon photonic circuits, then extinction ratio can be achieved, but fabrication imperfections cause uneven splitting leading to increased scrap rates and higher costs
Solution Approach 1:
The patent employs feedback mechanisms through phase shifters that actively adjust the phase of optical signals in real-time to compensate for fabrication imperfections. The system monitors the actual signal splitting and uses feedback control to equalize the paths, ensuring uniform signal distribution and improving manufacturing precision without sacrificing extinction ratio performance.
Solution Approach 2:
The patent utilizes parameter changes by dynamically adjusting the phase shift values in the phase shifter components. By changing the phase parameter of the optical signals, the system can compensate for fixed fabrication imperfections and achieve uniform signal splitting. This allows the same physical structure to perform optimally across different fabrication batches, reducing scrap rates.
2Reliability
If conventional optical signal splitting is used, then basic extinction function is achieved, but insertion losses are high and wavelength dependent
Solution Approach 1:
The patent introduces dynamic phase shifting capability to the otherwise static optical splitting structure. By making the phase shifters adjustable and responsive to control signals, the system can dynamically optimize the signal paths for different wavelengths and operating conditions. This dynamic adjustment reduces insertion losses across the wavelength spectrum while maintaining extinction ratio performance.
Solution Approach 2:
The patent designs the optical circuit to perform multiple functions: it achieves extinction ratio, compensates for wavelength variations, and minimizes insertion losses simultaneously. The phase shifter components serve both to create the necessary phase differences for extinction and to equalize signal paths for minimal loss, making the system universally effective across different operating conditions without requiring separate optimization for each function.
3Device complexity
If passive optical splitting is used, then simple structure is maintained, but extinction ratio is insufficient for activating downstream devices
Solution Approach 1:
The patent introduces phase shifters as intermediary components between the optical signal source and the final combining point. These phase shifters act as mediators that actively control the phase relationship between split signals, enabling precise extinction ratio control. The phase shifters provide the necessary phase adjustment without requiring complex non-linear optical elements, maintaining relative structural simplicity while achieving reliable extinction for downstream device activation.
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 scrap/failure rates, minimizes costs, and ensures consistent extinction ratios across varying wavelengths, enhancing the reliability and efficiency of optical signaling.
Implementation Method 1
a first phase shifter; and a second phase shifter, wherein the second phase shifter is configured to operate with the first phase shifter to phase offset the first partial signal relative to the second partial signal
Implementation Method 2
a first intensity modulator configured to provide a first matched signal based on the first partial signal; and a second intensity modulator configured to provide a second matched signal based on the second partial signal
Implementation Method 3
input optical signals are split and/or combined to produce various output optical signals of desired amplitudes. Extinction of an optical signal may occur by splitting an input optical signal into two signals and combining the two signals to interfere with one another
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Improvements in extinguishing optical signals in silicon photonics may be achieved by supplying a test signal of a known characteristics to a Photonic Element (PE) to extinguish the test signal via a first phase shifter and intensity modulator on a first arm of the PE and a second phase shifter and intensity modulator on a second arm of the PE; sweeping through a plurality of voltages at the first intensity modulator to identify a first voltage that is associated with an extinction ratio at an output of the PE that satisfies an induced loss threshold and a second voltage that is associated with an induced loss in the test signal at the output of the PE that satisfies an extinction ratio threshold; and setting the PE to provide an operational voltage to the first intensity modulator based on the first voltage and the second voltage.