Distributed-Phase-Shift Resonator for Compact Electro-Optic Modulators
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Solution Overview
Problem
Current electro-optic modulators, such as π Phase Shift Bragg resonators, experience high optical losses and require long core lengths, making them unsuitable for higher-density integrated photonic and mixed-signal circuits.
Innovation Solution
A distributed-phase-shift resonator with a sinusoidal grating profile along its core and non-phase-shift grating profiles on its reflectors, allowing for a shorter core length while maintaining high transmission levels and extinction ratios, is introduced.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a π Phase Shift Bragg resonator with apodized grating profile is used, then transmission levels and extinction ratios are improved, but core length increases significantly
Solution Approach 1:
The patent changes the grating profile parameters from apodized (tapered) to uniform amplitude with distributed phase shift. This parameter change allows the resonator to achieve high transmission and extinction ratio performance while maintaining a shorter core length, directly resolving the contradiction between reliability and length.
Solution Approach 2:
The patent introduces a sinusoidal phase modulation along the grating profile, creating a curved phase distribution rather than a linear or tapered amplitude profile. This curvature in the phase domain enables compact resonator design with improved performance metrics.
2Reliability
If a π Phase Shift Bragg resonator with apodized grating profile is used, then transmission levels and extinction ratios are improved, but device complexity increases
Solution Approach 1:
The patent simplifies the grating profile by using uniform amplitude instead of apodized amplitude variation, while compensating for performance requirements through distributed phase shift. This reduces manufacturing complexity while maintaining high extinction ratio.
Solution Approach 2:
The sinusoidal phase modulation provides a regular, predictable pattern that is easier to manufacture than apodized profiles, which require precise amplitude control varying along the grating length. The curved phase profile simplifies the fabrication process while achieving the desired extinction ratio.
3Length of moving object
If a distributed-phase-shift resonator with sinusoidal grating profile is used, then core length is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The sinusoidal phase modulation creates a smooth, continuous phase variation that is more tolerant to manufacturing variations compared to abrupt phase changes. The curved phase profile distributes the phase shift gradually, reducing sensitivity to fabrication imperfections.
Solution Approach 2:
The patent uses uniform grating amplitude with phase modulation instead of amplitude modulation, which simplifies the manufacturing process. The uniform amplitude profile is easier to fabricate with consistent precision, while the phase component can be controlled through standard photolithography techniques.
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 distributed-phase-shift resonator achieves nearly unity transmission levels and high extinction ratios with a significantly shorter core length compared to apodized designs, making it suitable for dense integrated circuits.
Implementation Method 1
a first side with a first grating profile having a first phase shift distributed between the first and second ends
Implementation Method 2
the optical structure is configured to resonate at an optical frequency when a first voltage is applied between the first and second electrodes
Implementation Method 3
the optical structure is configured to resonate at an optical frequency when a first voltage is applied between the first and second electrodes; the optical structure is configured to attenuate an optical signal at the optical frequency when a second voltage is applied between the first and second electrodes
Implementation Method 4
Bragg resonator
Implementation Method 5
the combination of the optical structure, the first reflector, and the second reflector is configured to resonate at the optical wavelength when a sum of the first, second, and third phase shifts equaling 360 degrees of the optical wavelength is imparted to an optical signal
Data Source
AI summary
An embodiment of an optical structure includes a core having first and second ends and a first side with a first grating profile having a first phase shift distributed between the first and second ends, and a cladding disposed around the core. Such an optical structure can be used in an electro-optic modulator (EOM), and can render the EOM smaller in size than currently available EOMs.