Hybrid Interferometer Disturbance Detection
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Solution Overview
Problem
Existing interferometer systems for detecting disturbances, such as those in security or surveillance applications, face limitations in accurately locating and measuring the magnitude of disturbances over long distances and in a timely manner due to costly polarization controllers and practical limitations on the number of sensing zones, leading to potential security vulnerabilities and inadequate spatial resolution.
Innovation Solution
The integration of a Michelson sensor with a Mach-Zehnder sensor using polarization-phase conjugation devices and a polarization scrambler allows for the detection of disturbances over long distances, providing accurate location and magnitude determination through phase shifts analysis, with a passively terminated fiber optic cable extending up to 65 km, and enabling rapid response to subsequent disturbances without the need for active polarization matching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If polarization controllers are used to match polarization states in Mach-Zehnder interferometer, then detection accuracy is improved, but system cost and complexity increase
Solution Approach 1:
The patent extracts and eliminates the polarization controller components from the interferometer system. By using a simplified interferometer configuration without polarization controllers, the system achieves cost reduction and complexity reduction while maintaining detection capability through alternative means of handling polarization effects.
Solution Approach 2:
The patent replaces expensive polarization controllers with a more economical approach using standard optical components and signal processing techniques. The system uses affordable alternatives such as simple beam splitters, mirrors, and electronic signal processing to achieve the same detection function at lower cost.
2Reliability
If polarization controllers are used to match polarization states, then signal correlation is improved, but response time to disturbances increases
Solution Approach 1:
The patent performs preliminary actions by pre-configuring the interferometer system with fixed optical path lengths and using electronic signal processing to continuously monitor for disturbances. This eliminates the need for real-time polarization matching, allowing immediate detection of disturbances without delay.
Solution Approach 2:
The patent substitutes the mechanical polarization control system with an electronic signal processing system. Instead of using physical polarization controllers to match states, the system uses electronic correlation algorithms to process and compare signals from the interferometer arms, achieving faster response times.
3Measurement precision
If multiple sensing zones are created using light splitting, then spatial resolution is improved, but system cost and complexity increase
Solution Approach 1:
The patent segments the sensing function by creating multiple independent sensing zones along the optical path. Each zone can be independently monitored for disturbances, achieving high spatial resolution. The segmentation is accomplished through strategic placement of optical components and signal processing techniques rather than complex system architecture.
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 hybrid interferometer system effectively detects and locates disturbances within a few seconds over distances of up to 65 km, offering improved spatial resolution and reducing the risk of security breaches by eliminating the need for costly and time-consuming polarization state matching, thus enhancing perimeter security systems.
Implementation Method 1
a first polarization-phase conjugation device conjugating a polarization phase of incident light corresponding to the first fiber portion, and a second polarization-phase conjugation device conjugating a polarization phase of incident light corresponding to the second fiber portion
Implementation Method 2
The innovations disclosed herein pertain to interferometer systems... a Mach-Zehnder interferometer can detect a phase-shift between two beams of light split from a single collimated beam
Implementation Method 3
a polarization scrambler configured to randomize a polarization state of light entering the first and second fiber sensor portions
Data Source
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AI summary
A fiber-optic sensor can have a Michelson sensor portion and a Mach-Zehnder sensor portion. A first splitter-coupler can be configured to split incoming light between a first fiber portion and a second fiber portion. A first polarization-phase conjugation device can be configured to conjugate a polarization phase of incident light corresponding to the first fiber portion, and a second polarization-phase conjugation device can be configured to conjugate a polarization phase of incident light corresponding to the second fiber portion. Each of the first and second polarization-phase conjugation devices can be configured to reflect light toward a detector and through the respective first and second fiber portions. A coupler can be configured to join light in the first fiber portion with light in the second fiber portion, and a third fiber portion can be configured to receive light from the coupler and to illuminate a second detector.