Optical Tomographic Imaging Apparatus Using Wavelength Division
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional OCT systems face challenges in obtaining high-resolution tomographic images rapidly due to limitations in detector arrays and synchronization requirements when using multiple light sources, leading to reduced measuring rates and increased costs.
Innovation Solution
An optical tomographic imaging apparatus that employs two light sources with overlapping wavelength ranges, where the interference beams are divided into distinct wavelength ranges for detection, allowing simultaneous irradiation of the measuring object without mixing interference signals and eliminating the need for synchronization control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a detector array with more elements is used to increase the number of data points for high resolution imaging, then the measurement precision is improved, but the device complexity and cost increase
Solution Approach 1:
The invention divides the broadband light beam into multiple wavelength bands using optical filters, and detects each band separately with a single photodetector. This segmentation of the spectral range allows achieving high measurement precision without requiring a complex multi-element detector array, thus resolving the contradiction between image resolution and device complexity
Solution Approach 2:
Instead of increasing the number of spatial detection elements (2D array), the invention transitions to spectral dimension by measuring intensity at multiple discrete wavelength points across the broadband spectrum. This dimensional shift from spatial to spectral domain enables high-resolution imaging with a simple single-element detector
2Measurement precision
If multiple light sources with different wavelength ranges are used to broaden the spectral width, then the measurement precision is improved, but the device complexity and synchronization requirements increase
Solution Approach 1:
The invention merges the functions of multiple light sources into a single broadband light source that emits across the entire spectral range needed for high-resolution imaging. This eliminates the need for complex synchronization control between multiple sources while achieving the same measurement precision benefit
Solution Approach 2:
A single broadband light source performs the function that previously required multiple wavelength-specific sources, providing universal coverage across the entire spectral range. This multi-functional approach simplifies the system by eliminating separate light source subsystems and their associated synchronization controls
3Measurement precision
If the number of data points is increased for high resolution imaging, then the measurement precision is improved, but the productivity decreases due to increased processing time
Solution Approach 1:
Instead of continuously sweeping through the entire spectral range or using a full spectral detector, the invention selectively measures intensity at a sufficient number of discrete wavelength points. This partial sampling approach provides adequate measurement precision for high-resolution imaging while maintaining fast acquisition speed and high productivity
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 enhances the measuring rate and resolution of tomographic images by enabling the detection of interference signals within specific wavelength ranges, improving image quality and simplifying the apparatus design.
Implementation Method 1
the measuring beam is irradiated onto a measuring object, then the reflected beam from the measuring object or backscattered light when the measuring beam is irradiated thereon is combined with the reference beam, and an optical tomographic image is obtained based on the intensity of the interference beam between the reflected beam and the reference beam
Implementation Method 2
the interference beam is broken down into frequency components using a spectroscopic device
Implementation Method 3
the intensity of the interference beam with respect to each frequency component is measured using a detector array including elements, such as photodiodes
Data Source
AI summary
Light beams swept in wavelength repeatedly within first and second wavelength ranges respectively are outputted from a light source unit at the same time. Each light beam is split into measuring and reference beams. Reflected beams from a measuring object when the measuring beams are irradiated on the measuring object are combined with the reference beams. The wavelengths of the interference beams produced thereby are divided into three wavelength ranges, for example, a range not greater than 0.9 μm, a range from 0.9 to 1.2 μm, and a range longer than 1.2 μm by a wavelength dividing means to obtain interference signals. In the wavelength range from 0.9 to 1.2 μm which includes an overlapping wavelength range where the wavelength ranges of the light beams overlap with each other, either one of the light beams is outputted from the light source unit.