Charge-Discharge Microring Modulator With Dual Tunable Couplers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Microring electro-optical modulators face significant performance degradation due to energy decay in the ring resonator over time, limiting modulation speed and depth, especially when constrained by the resonator's Q factor.
Innovation Solution
The implementation of an optical ring resonator with two tunable optical couplers and control circuitry that modulates the coupling coefficients using control signals to maintain a constant electrical-field complex envelope, with an auxiliary optical signal compensating for energy loss, allowing for independent amplitude control and improved modulation performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single optical coupler is used to modulate the input optical signal, then the device complexity is reduced, but energy decay in the ring resonator causes performance degradation over time
Solution Approach 1:
The single optical coupler is segmented into two separate optical couplers: a first optical coupler for modulating the input optical signal and a second optical coupler for compensating energy decay. This segmentation allows independent optimization of each coupler's function, with the first coupler handling modulation and the second coupler maintaining constant energy levels in the resonator, thereby resolving the contradiction between device simplicity and performance stability.
Solution Approach 2:
An auxiliary optical signal is introduced as an intermediary element to compensate for energy decay in the ring resonator. This auxiliary signal, coupled through the second optical coupler, acts as a mediator that restores energy lost during modulation operations, enabling sustained high-performance modulation without requiring complex feedback mechanisms.
2Productivity
If the resonator operates at high modulation speeds, then productivity is improved, but energy decay increases and limits modulation depth
Solution Approach 1:
The system maintains continuous energy compensation in the ring resonator through the second optical coupler, which continuously injects energy to offset decay losses. This continuous action enables the resonator to sustain high modulation speeds without experiencing cumulative energy depletion, thereby achieving both high productivity and minimal energy loss.
Solution Approach 2:
The coupling coefficients of both optical couplers are dynamically adjusted based on the modulation state. The first coupler's coupling coefficient is modified to achieve desired modulation depth, while the second coupler's coupling coefficient is simultaneously adjusted to compensate for energy decay. This coordinated parameter change enables high-speed modulation with maintained energy levels.
3Reliability
If the resonator's Q factor is increased to reduce energy decay, then reliability is improved, but the resonator becomes more sensitive to coupling coefficient variations
Solution Approach 1:
The system implements a feedback mechanism where the coupling coefficients of both optical couplers are dynamically adjusted based on the operational state of the resonator. This feedback control allows the system to compensate for sensitivity to coupling variations by continuously adapting the coupling strengths, thereby maintaining high Q factor benefits while mitigating the harmful effects of coupling sensitivity.
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 configuration achieves high modulation speed and depth, prevents energy decay, and enables straightforward cascading of multiple modulators, overcoming limitations imposed by the resonator's Q factor and maintaining accurate modulation without distortion.
Implementation Method 1
an optical ring resonator with two tunable optical couplers and control circuitry that modulates the coupling coefficients using control signals to maintain a constant electrical-field complex envelope
Implementation Method 2
The first optical coupler is configured to modulate an input optical signal traversing an optical waveguide, by tuning the energy cross-coupling between the optical waveguide and the ring resonator with a first variable coupling coefficient
Data Source
AI summary
An apparatus includes an optical ring resonator, first and second optical couplers, and control circuitry. The first optical coupler is configured to modulate an input optical signal traversing an optical waveguide, by tuning cross-coupling of energy between the optical waveguide and the ring resonator with a first variable coupling coefficient. The second optical coupler is configured to tune cross-coupling of energy between the ring resonator and an auxiliary optical signal, different from the input optical signal, with a second variable coupling coefficient. The control circuitry is configured to modulate the first coupling coefficient with a first control signal so as to modulate the input optical signal, and to modulate the second coupling coefficient with a second control signal, so as to retain a constant electrical-field complex envelope in the ring resonator.