Optical Imaging System Spatial Coherence Structure Speckle Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional 4f optical imaging systems suffer from imaging quality degradation and low signal-to-noise ratio when the frequency plane is partially occluded, especially with coherent illumination, which results in speckles, and incoherent illumination leads to low light utilization and high noise.
Innovation Solution
An optical imaging system and method utilizing a spatial coherence structure, including a light source assembly, obstacle optical assembly, adjustable optical assembly, and detection assemblies, where a spatial light modulator adjusts the beam to pass through an opening in the obstacle, enabling coherent imaging without speckles and improving light utilization and signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If coherent illumination is used in a 4f imaging system, then imaging resolution is improved, but speckles are generated and imaging quality deteriorates when the frequency plane is partially occluded
Solution Approach 1:
The patent changes the coherence parameter of the light source from fully coherent to partially coherent by introducing a spatial coherence structure. This is achieved by controlling the spatial distribution of the light source, which modifies the coherence properties of the illuminating light to eliminate speckles while preserving imaging resolution.
Solution Approach 2:
The patent employs a spatial light modulator to dynamically adjust and regulate the spatial coherence structure of the incident light. This dynamic control allows the system to optimize the coherence properties in real-time, enabling the light to pass through obstacles while maintaining high-resolution imaging without speckles.
2Object-affected harmful factors
If incoherent illumination is used in a 4f imaging system, then speckles are eliminated, but light utilization rate decreases and signal-to-noise ratio deteriorates
Solution Approach 1:
The patent optimizes the coherence parameter to a partial coherence state rather than using fully incoherent light. By carefully designing the spatial coherence structure, the system achieves a balance that eliminates speckles while maintaining high light utilization rate and signal-to-noise ratio, avoiding the energy loss associated with fully incoherent illumination.
3Reliability
If the frequency plane is partially occluded by an external obstacle, then imaging quality is seriously affected, but the system should maintain robust imaging capability
Solution Approach 1:
The patent uses a spatial light modulator to dynamically regulate the spatial coherence structure, allowing the system to adapt when the frequency plane is partially occluded. By adjusting the coherence properties, the system can bypass obstacles and maintain robust imaging quality that would otherwise be seriously degraded by external obstructions.
Solution Approach 2:
The patent applies different coherence properties to different regions of the light field. By locally optimizing the spatial coherence structure in different areas of the beam, the system ensures that light can pass through obstacles while maintaining overall imaging quality and robustness.
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 system achieves robust imaging without speckles and enhances light utilization and signal-to-noise ratio by designing a spatial coherence structure that allows all modes of the incident beam to pass through the obstacle, improving imaging quality even when the frequency plane is partially occluded.
Implementation Method 1
a spatial light modulator adjusts the beam to pass through an opening in the obstacle, enabling coherent imaging without speckles
Implementation Method 2
a light source assembly including a laser and a first beam split element, the first beam split element splitting a beam emitted from the laser
Implementation Method 3
a 4f imaging system contains two strict Fourier transform processes, which enables researchers to analyze and process the spectrum of optical information
Data Source
AI summary
The invention discloses an optical imaging system and an imaging method regulated based on a spatial coherence structure, including the steps of: building a 4f imaging system; detecting, by a first optical detector, the shape of the spectrum domain obstacle in the 4f imaging system; designing a spatial coherence structure of the incident beam based on the shape of the spectrum domain obstacle, so that all the modes of the incident beam can pass through the opening in the obstacle; and placing an object to be detected in the optical path and detecting, by the second optical detector, the optical imaging information of the object to be detected. According to the present invention, in the case where the frequency plane of the 4f optical imaging system is partially occluded, imaging without speckles is enabled, utilization of the systematic light is substantially improved, and the signal-to-noise ratio in imaging is improved.