Full-Field Optical Coherence Microscopy with Parallel Detection
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Solution Overview
Problem
Conventional optical coherence tomography (OCT) methods, particularly full-field Fourier domain OCT, face challenges such as the need for highly stable interferometer environments, limited imaging speed, and issues with interpreting depth images due to symmetrical images and parasitic noise from internal reflections, which hinder the achievement of full-range imaging.
Innovation Solution
A 3D imaging system utilizing a two-beam orthogonally polarized interferometer with achromatic wave plates and parallel detectors to capture simultaneous phase-shifted interference signals, allowing for ultra-high speed and accurate imaging with reduced noise immunity, enabling full-range imaging without mechanical scanning or optical modulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional full-field Fourier domain OCT is used to achieve high speed imaging, then imaging speed is improved, but the system requires highly stable interferometer environment which reduces reliability in practical applications
Solution Approach 1:
The patent replaces mechanical scanning systems with parallel detection architecture. Multiple detectors capture multiple phase-shifted images simultaneously, eliminating the need for mechanical phase modulation and reference mirror scanning. This substitution of mechanical systems with parallel electronic detection achieves high imaging speed while removing the requirement for highly stable interferometer environments.
Solution Approach 2:
The patent segments the interference signal detection into multiple parallel channels, each detecting a different phase-shifted image. By dividing the measurement into simultaneous parallel detections rather than sequential mechanical scanning, the system achieves high speed imaging without requiring mechanical stability, as all measurements are captured at once.
2Measurement precision
If phase-shifted images are acquired at different time slots to achieve depth morphology, then depth resolution is improved, but imaging speed deteriorates due to sequential acquisition
Solution Approach 1:
The patent segments the detection process into multiple parallel channels, with each channel detecting a different phase-shifted image simultaneously. This parallel segmentation allows all phase information needed for depth resolution to be captured at the same time, eliminating the sequential time-slot acquisition that limits imaging speed.
Solution Approach 2:
The patent transitions from temporal sequencing to spatial parallelism by using multiple detectors arranged in different detection channels. Instead of acquiring phase-shifted images at different times (temporal dimension), the system captures them simultaneously across multiple spatial detection channels, achieving both high depth resolution and high imaging speed.
3Reliability
If frequency domain OCT with spectral sweeping is used to improve signal to noise ratio, then SNR is improved, but the system requires complex optical modulation which increases device complexity
Solution Approach 1:
The patent replaces complex optical modulation systems (spectral sweeping, acousto-optic modulators) with a simpler parallel detection architecture. Multiple detectors directly capture phase-shifted interference patterns without requiring spectral modulation, achieving high SNR through parallel signal acquisition while dramatically reducing device complexity.
Solution Approach 2:
The patent extracts the phase-shifted interference signals directly through parallel detection channels, removing the need for complex optical modulation components. By taking out the modulation step and using direct parallel detection, the system achieves high SNR with simpler optics.
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 ultra-high resolution and speed in OCT imaging with immunity to vibrational and intensity noise, overcoming previous limitations by capturing phase and amplitude signals simultaneously and eliminating mirror image and DC noise, thus facilitating clearer interpretation of sample structures.
Implementation Method 1
the two beams are recombined and projected onto three parallel detectors equipped with achromatic phase shifters to capture three simultaneous phase-shifted interference images
Implementation Method 2
achromatic phase shifters to capture three simultaneous phase-shifted interference images
Implementation Method 3
OCT relies on the light temporal coherence, interference and matter reflectivity (refraction index discontinuity) which are used to measure micro morphology of objects in a turbid environment
Implementation Method 4
the two beams are recombined and projected onto three parallel detectors equipped with achromatic phase shifters to capture three simultaneous phase-shifted interference images
Data Source
AI summary
The invention is a system and method that enable obtaining ultra-high resolution interference, phase and OCT images at high speed. The system uses neither mechanical moving elements nor any optical/electro optical modulating means for obtaining the OCT images. Two OCT operating modes are available: for ultra-high resolution the system allows either spatial coherence TD-FF-OCT or temporal coherence TD-FF-OCT imaging, whereas for high resolution and ultra-high speed the system allows FD-FF-OCT imaging with full range imaging. In the TD mode, the OCT enface images are obtained in real time. In the FD mode, the 2D complex signal is reconstructed in real time. In both cases the method has the advantage of very high speed imaging with great immunity to noise.