Double-Clad Fiber Imaging for Resolution and Throughput
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Single-mode optical fibers used in endoscopy suffer from poor light throughput, speckle noise, and limited depth of field, which restricts image quality and flexibility in medical and non-medical applications.
Innovation Solution
Employing a double-clad optical fiber where the core is used for illumination and the inner cladding for signal collection, or vice versa, to reduce speckle noise, increase depth of field, and enhance signal efficiency, allowing for both single-mode illumination and multi-mode detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single-mode optical fiber is used for illumination, then high resolution imaging is achieved, but light throughput is poor and speckle noise is introduced
Solution Approach 1:
The optical fiber is segmented into distinct functional regions: the core is dedicated to illumination while the cladding is dedicated to signal collection. This segmentation allows each region to be optimized for its specific function, enabling single-mode illumination through the core while collecting light through the multi-mode cladding, thereby resolving the contradiction between resolution and light throughput
Solution Approach 2:
The optical fiber is designed to perform multiple functions simultaneously: the core provides single-mode illumination for high resolution, while the cladding provides multi-mode signal collection for increased light throughput. This multi-functionality allows the single fiber to overcome the limitations of using only single-mode or only multi-mode fibers
2Measurement precision
If a single-mode optical fiber is used, then high resolution imaging is achieved, but speckle noise significantly reduces image quality
Solution Approach 1:
By segmenting the fiber into core and cladding with distinct functions, the illumination path (core) and detection path (cladding) are separated. This allows the use of single-mode illumination in the core for resolution while the multi-mode cladding collects light from multiple paths, averaging out the speckle noise and improving overall image quality
Solution Approach 2:
The cladding acts as an intermediary that collects light scattered from the sample and guides it back to the detector. By using the cladding for signal collection rather than the core, the system mediates between the coherent single-mode illumination and the detector, reducing the direct transmission of speckle noise while maintaining resolution
3Measurement precision
If a single-mode optical fiber is used, then high resolution imaging is achieved, but depth of field is limited
Solution Approach 1:
The functional segmentation of core and cladding allows the system to achieve optical sectioning through single-mode illumination in the core while the larger-clad collection aperture increases the depth of field. This resolves the contradiction by separating the resolution-providing function from the depth-of-field-providing function
4Loss of energy
If a multi-mode optical fiber is used, then light throughput and signal efficiency are improved, but point-spread function deteriorates and interferometry for three-dimensional detection is prevented
Solution Approach 1:
The fiber is segmented into core and cladding where the core maintains single-mode properties for excellent point-spread function and interferometric capability, while the cladding provides multi-mode signal collection for high light throughput. This segmentation allows simultaneous achievement of both resolution and signal efficiency
Solution Approach 2:
The optical fiber is designed with multi-functionality: the core provides single-mode illumination and coherent signal collection for high resolution and interferometry, while the cladding provides additional light collection pathways for increased throughput. This dual-function design resolves the contradiction between maintaining point-spread function and increasing light throughput
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 improves image quality by reducing speckle noise, increasing depth of field, and enhancing signal efficiency, enabling more effective three-dimensional imaging and flexible endoscopic applications.
Implementation Method 1
transmitting a first propagating mode of light through the core of the optical fiber
Implementation Method 2
collecting scattered light from the sample in at least a first one of the at least one cladding regions
Data Source
AI summary
A method and apparatus for imaging using a double-clad fiber is described.