Spectral Imaging Coherence Noise Reduction via Wavenumber Modulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current spectral imaging systems face challenges in improving the resolution and quality of spectral images due to interference patterns caused by coherence noise from standing wave or multiple beam physics, which affects data acquisition speed and throughput.
Innovation Solution
A spectral imaging device that includes a tunable light source, an image sensor, and a control system, where the control system modulates the center wavenumber of the illumination beam at a rate greater than or equal to the frame rate of the image sensor, reducing peak-to-peak interference patterns and coherence noise by using a modulation rate that is an integer multiple of the frame rate, thereby enhancing image quality and data acquisition speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the illumination beam uses substantially coherent light to improve spectral image quality, then measurement precision is improved, but object-generated harmful factors worsen due to coherence noise from standing wave or multiple beam physics
Solution Approach 1:
The patent applies periodic modulation to the center wavenumber of the illumination beam at a rate greater than or equal to the frame rate of the image sensor. This periodic action causes the coherence noise patterns to fluctuate rapidly, and by capturing multiple frames and averaging them, the noise is reduced while the spectral information is preserved. The modulation rate being an integer multiple of the frame rate ensures synchronized sampling that maximizes noise cancellation.
2Measurement precision
If the modulation rate is increased to reduce coherence noise, then measurement precision is improved, but device complexity increases due to synchronization requirements between light source and image sensor
Solution Approach 1:
The control system implements feedback by synchronizing the modulation of the light source with the frame capture rate of the image sensor. The modulation rate is set to be an integer multiple of the frame rate, creating a locked relationship between the two components. This feedback mechanism ensures that the coherence noise is consistently modulated across frames, enabling effective noise reduction through averaging while maintaining systematic control.
3Productivity
If data acquisition speed is increased to improve productivity, then productivity is improved, but measurement precision worsens due to reduced averaging of coherence noise
Solution Approach 1:
By modulating the illumination beam's center wavenumber periodically at a rate synchronized with or faster than the frame rate, the system enables rapid acquisition of multiple frames with varying coherence noise patterns. This periodic modulation allows the system to capture sufficient frames for noise averaging even at high speeds, maintaining image quality while improving data acquisition 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
The solution significantly improves the quality of spectral images and increases data acquisition speed by minimizing coherence noise associated with standing wave or multiple beam physics, resulting in higher resolution and faster data processing.
Implementation Method 1
temporally coherent illumination beam
Implementation Method 2
coherence noise sources of the spectral imaging device associated with standing wave or multiple beam physics
Data Source
AI summary
A spectral imaging device (12) for generating an image (13A) of a sample (10) includes (i) an image sensor (30); (ii) a tunable light source (14) that generates an illumination beam (16) that is directed at the sample (10); (iii) an optical assembly (22) that collects light from the sample (10) and forms an image of the sample (10) on the image sensor (30); and (iv) a control system (32) that controls the tunable light source (14) and the image sensor (30). During a time segment, the control system (32) (i) controls the tunable light source (14) so that the illumination beam (16) has a center wavenumber that is modulated through a first target wavenumber with a first modulation rate; and (ii) controls the image sensor (30) to capture at least one first image at a first frame rate. Further, the first modulation rate is equal to or greater than the first frame rate.