Silicon Optical Modulator Pre-Chirping via Coupling Ratio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Silicon optical modulators require higher voltages for pre-chirping, leading to complex electric circuits and larger configurations, making it difficult to achieve size reduction in optical transmitters while maintaining effective signal quality.
Innovation Solution
A Mach-Zehnder optical modulator with a silicon optical waveguide path that applies pre-chirping by adjusting the coupling ratio of the optical coupler, rather than controlling the voltage applied to the arms, to generate the necessary phase difference for the optical modulation signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a silicon optical modulator is used instead of an LN modulator to reduce device size, then the size of the optical modulator is reduced from centimeters to millimeters, but a higher voltage needs to be applied to the electrode to achieve the same phase change, resulting in complex electric circuits and larger configuration
Solution Approach 1:
The patent replaces the electrical control method (applying voltage to electrodes) with an optical control method (adjusting coupling ratio in the optical path). This substitution eliminates the need for complex high-voltage electric circuits while achieving the same pre-chirping effect through optical parameter adjustment, thereby resolving the contradiction between size reduction and circuit complexity
Solution Approach 2:
The patent changes the control parameter from electrical voltage to optical coupling ratio. By adjusting the coupling ratio parameter in the optical domain rather than the electrical domain, the system achieves pre-chirping functionality without requiring complex voltage control circuits, thus resolving the contradiction between compact size and circuit complexity
2Reliability
If a higher voltage is applied to the electrode of the silicon optical modulator to achieve pre-chirping, then the pre-chirping effect is achieved, but the electric circuit becomes large scale and control becomes complex
Solution Approach 1:
The patent substitutes electrical voltage control with optical coupling ratio adjustment. This replacement maintains the pre-chirping effect while eliminating the complexity of high-voltage control, thereby improving ease of operation without sacrificing reliability
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 allows for the application of pre-chirping with a simpler configuration, reducing the size of the optical modulator and improving transmission quality by effectively managing dispersion-induced waveform degradation without the need for complex voltage control circuits.
Implementation Method 1
an optical coupling means for coupling output light from the first arm and output light from the second arm at a predetermined coupling ratio and generating an optical modulation signal
Implementation Method 2
The arms 911 and 912 each include an electrode, and a phase of the continuous light is modulated by applying a voltage to each electrode
Data Source
AI summary
In order to apply pre-chirping to an optical modulation signal by a simple configuration, an optical modulator includes: an optical splitter that splits input light into two light beams; a first arm and a second arm that modulate the two light beams split by the optical splitter, respectively, by transmission data; and an optical coupler that couples output light of the first arm and output light of the second arm at a predetermined coupling ratio to generate an optical modulation signal, and the optical splitter, the first and second arms and the optical coupler are configured so as to operate as a Mach-Zehnder optical modulator, and the coupling ratio of the optical coupler is set such that predetermined pre-chirping is applied to the optical modulation signal.