Phase Mask Corrects Fiber Bundle Crosstalk
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flexible endoscopes suffer from low image contrast due to pixelation and crosstalk between fibers, as well as the inability to directly access phase information, leading to blurred images and limitations in far-field illumination.
Innovation Solution
A method involving determining the system function of a coherent optical fiber bundle, arranging a phase mask to correct transmission interference, and using proximal illumination with the phase mask to adaptively correct the light transmission, allowing for coherent phase array functionality without surface light modulators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If flexible fiber bundles are used for compactness and flexibility, then accessibility and compactness are improved, but image contrast deteriorates due to pixelation and crosstalk
Solution Approach 1:
The patent applies preliminary action by pre-calibrating the fiber bundle to determine the system function (point spread function) before actual imaging. This calibration data is stored and used to computationally correct the blurred images, effectively addressing the pixelation and crosstalk issues that inherently limit image contrast in flexible fiber bundles.
2Loss of information
If conventional fiber bundles are used for light transmission, then intensity profiles can be transmitted, but phase information is lost due to varying optical path lengths
Solution Approach 1:
The patent introduces an intermediary computational step between the fiber bundle and the final image. The system function (point spread function) acts as a mediator that characterizes the phase distortions introduced by the fiber bundle. By convolving this system function with the captured image and applying deconvolution algorithms, the phase information is recovered without requiring complex physical modifications to the fiber bundle itself.
3Measurement precision
If wavefront sensors and modulators are used for adaptive optics, then phase aberrations can be corrected, but device complexity and cost increase
Solution Approach 1:
The patent replaces the mechanical/optical adaptive optics system (wavefront sensors and modulators) with a computational approach. Instead of using physical devices to measure and correct phase aberrations in real-time, the system pre-characterizes the fiber bundle's optical properties and uses digital signal processing to correct the images computationally, thereby eliminating complex and expensive adaptive optics hardware.
4Measurement precision
If digital optical phase conjugation is used for turbidity suppression, then phase distortions can be corrected, but complex calibration and adjustment are required
Solution Approach 1:
The patent applies self-service by having the fiber bundle itself provide the calibration data needed for correction. The system function is determined by measuring the actual transmission properties of the specific fiber bundle being used, making the calibration intrinsic to each individual bundle. This eliminates the need for complex external calibration procedures and adjustments, as each fiber bundle self-characterizes its own optical properties.
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 improved image quality by correcting interference and maintaining phase information, facilitating pixel-free and diffraction-limited imaging with preserved phase data, suitable for applications like 3D imaging and optogenetics.
Implementation Method 1
a coherent bundle of optical fibers (1) is illuminated with light (21) emitted by an illumination system (2) at its proximal fiber end (11)
Implementation Method 2
a phase mask (5) is arranged in a form-fitting manner at at least one fiber end (11, 12) of the bundle of optical fibers (1), wherein the phase mask (5) is designed in such a way that at least the inverse of the system function is imprinted on the light (21, 22, 23)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a method and an arrangement (4, 4') for the adapted illumination of an object with light. According to the invention, the system function of a flexible bundle of optical fibers (1) is corrected by the form-fitting, additive or subtractive arrangement of a phase mask (5, 5') on at least one of the fiber ends (11) of the fiber bundle (1), which corrects at least the transmission disturbances caused by the fiber bundle (1), so that a coherent phase array is available for imaging the object. The method and the arrangement (4, 4') according to the invention make it possible to obtain three-dimensional information about an object using a flexible bundle of optical fibers (1) without integrating imaging optics.