Optical Single-Sideband Transmitter Using Reflection Modulators
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Solution Overview
Problem
Existing methods for generating optical single sideband (SSB) modulation are inefficient and not well-suited for integration in photonic integrated circuits (PICs due to their large size and complexity.
Innovation Solution
A compact SSB modulation architecture using reflection-mode electro-absorption modulators (REAMs) in a Michelson Interferometer, with adjustable optical path lengths and phased electrical signals, allowing for efficient generation of SSB signals suitable for PIC integration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Mach-Zehnder Interferometer (MZI) arrangements are used for optical SSB generation, then optical SSB modulation can be achieved, but the device size becomes large (several cm long) and complexity increases
Solution Approach 1:
The patent replaces the traditional MZI mechanical/optical phase modulation system with a microring resonator-based system that uses optical resonance and coupling effects. This substitution dramatically reduces the device footprint from several cm to a much more compact structure while maintaining SSB modulation functionality through resonant enhancement effects
Solution Approach 2:
The patent changes the operating parameters by utilizing resonant frequencies of the microring structure. By operating at specific resonance conditions and controlling the coupling between the bus waveguide and ring resonator, the system achieves enhanced modulation efficiency and compact size simultaneously
2Reliability
If traditional MZI arrangements are used, then optical SSB can be generated, but the structure is not well suited to optical integration in photonic integrated circuits
Solution Approach 1:
The patent merges the modulation function with the resonator structure itself. The microring resonator simultaneously provides wavelength filtering, resonance enhancement, and modulation functionality, eliminating the need for separate MZI components and making the structure ideal for photonic integrated circuit fabrication
Solution Approach 2:
The microring resonator structure serves multiple functions: it acts as a wavelength-selective filter, provides resonance enhancement for low-power operation, and enables SSB modulation through its coupling characteristics. This multi-functionality simplifies the overall device architecture and improves manufacturability
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 compact architecture enables efficient SSB modulation with reduced size, wide bandwidth, and low operating voltage, making it ideal for PIC implementations and improving spectral efficiency in optical fiber telecommunications and sensor networks.
Implementation Method 1
intensity reflection-modulating each part with electrical signals
Implementation Method 2
splitting an optical field into two parts and introducing a relative phase delay
Implementation Method 3
The optical splitting, combining and phase delay means may be performed by silica on silicon waveguides
Data Source
AI summary
A method for generating an optical single sideband signal comprising the steps of splitting an optical field into two parts and introducing a relative phase delay of +/−π/4 radians in each direction of transmission to one of the parts, intensity reflection-modulating each part with electrical signals having a relative phase delay of +/−π/2 radians and then recombining the reflection-modulated signals.