Acoustic Sensor Frequency Response Shaping via Optical Fiber Wrapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current fiber optic acoustic sensors face limitations in shaping their frequency response, which affects their sensitivity and ability to detect specific frequency bands of interest, as the wrapping pattern of optical fiber around the core significantly influences the sensor's performance.
Innovation Solution
A method is developed to determine a wrapping pattern for optical fiber around a core based on the desired frequency response, using an inverse Fourier transform to derive the impulse response, allowing for the precise shaping of the frequency response by varying the number and arrangement of optical fiber layers along the core.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the wrapping pattern of optical fiber around the core is varied to shape the frequency response, then the sensor's sensitivity and ability to detect specific frequency bands is improved, but the manufacturing complexity increases
Solution Approach 1:
The optical fiber wrapping is divided into multiple discrete layers wound around the core at different positions. Each layer can be independently controlled in terms of its position and configuration, allowing the frequency response to be shaped by adjusting individual layers rather than requiring a complex continuous wrapping pattern.
Solution Approach 2:
Different sections of the core are wrapped with optical fiber to different extents, creating local variations in the wrapping pattern. The wrapping density and position are optimized at specific locations along the core to achieve the desired frequency response characteristics, rather than applying a uniform wrapping pattern throughout.
2Reliability
If the number and arrangement of optical fiber layers are optimized to enhance sensitivity, then the sensor's ability to detect specific sound waves is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The optical fiber wrapping is segmented into multiple discrete layers that can be independently positioned and configured around the core. This segmentation allows for optimized sensitivity by adjusting individual layers without requiring complex coordinated movements, simplifying the manufacturing process while maintaining high sensor performance.
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 enables the creation of acoustic sensors with tailored frequency responses, enhancing their sensitivity and ability to detect specific sound waves by optimizing the wrapping pattern, thereby improving the sensor's performance in acoustic sensing applications.
Implementation Method 1
Optical interferometry may be used to detect the dynamic strain along a segment of the fiber. Optical interferometry is a technique in which two separate light pulses, a sensing pulse and a reference pulse, are generated and interfere with each other.
Implementation Method 2
Pressure changes, due to sound waves for example, in the space immediately surrounding an optical fiber and that encounter the optical fiber, cause dynamic strain in the optical fiber.
Implementation Method 3
The fiber Bragg gratings partially reflect the pulses back towards an optical receiver at which an interference pattern is observed.
Implementation Method 4
The wrapping pattern is determined from an impulse response of the acoustic sensor. The impulse response is determined from the desired frequency response of the acoustic sensor.
Data Source
AI summary
There is described a method of making an acoustic sensor having a frequency response approximating a desired frequency response. The method comprises wrapping optical fiber around a core according to a wrapping pattern. The wrapping pattern is determined from an impulse response of the acoustic sensor. The impulse response is determined from the desired frequency response of the acoustic sensor.