What Is Optical Coherence Tomography?

Optical Coherence Tomography (OCT) is a high-resolution, non-invasive, three-dimensional imaging technology based on the principle of low-coherence interferometry, widely used in medicine, materials science, industrial inspection and other field.

Principle

Optical Coherence Tomography (OCT) systems utilize backscattered or reflected light signals to generate high-resolution, 2D or 3D structural images of samples at varying depth layers. The advanced 3D imaging capabilities of OCT allow for real-time dynamic imaging with micrometer-level resolution, all while mitigating radiation risks. These unique features make OCT an indispensable tool in early disease diagnosis, material defect detection, and multi-layer structure research. The utilization of OCT technology in these applications highlights its significance in the field of biomedical imaging and materials science.

Composition

The OCT system is predominantly composed of several fundamental components: a super-broadband light source, an interferometer, a scanning apparatus, a detector, and a data processing unit. The super-broadband light source provides a broadband beam with high spatial resolution, which is split into sample and reference paths by the interferometer and then recombined to form an interference pattern. To obtain 2D or 3D imaging, the scanning apparatus is used to perform lateral scanning of the sample. The detector captures these interference signals and converts them into electrical signals. Ultimately, the data processing unit is tasked with signal processing and image reconstruction, converting the interference signals into visualized three-dimensional images.

Applications

a. Medical diagnosis

Optical Coherence Tomography (OCT) has become a standard diagnostic tool in ophthalmology for detecting retinal diseases, glaucoma, and macular degeneration. Additionally, OCT is utilized in the cardiovascular field to assess atherosclerotic plaques and coronary artery stenosis. In dermatology, it is employed non-invasively to examine skin lesions such as melanomas and skin cancers. In dentistry, OCT is used to evaluate the health of teeth and periodontal tissues.

b. Life Sciences

In tissue engineering, OCT is employed to analyze the internal structure and porosity distribution of biomaterials and scaffolds, and to monitor cell growth on scaffolds in real-time, evaluating cell distribution and density. OCT is also utilized to image brain tissues in small animal models, aiding in the understanding of neural networks and disease mechanisms in neuroscience. Additionally, in plant science, OCT is employed to investigate the internal structure and growth processes of plants.

c. Industrial Inspection

OCT is primarily utilized in industrial inspection to detect internal defects in materials. In the semiconductor industry, it inspects wafer quality, identifying surface defects and internal structures. In composite materials, OCT detects internal flaws such as bubbles, cracks, and delamination. Additionally, OCT measures coating thickness, assesses the uniformity of coatings, and inspects the quality of optical fiber connectors and joints in fiber optic communications

In conclusion, OCT has played a crucial role in various fields, including medical diagnosis, industrial inspection, cultural heritage preservation, and scientific research, owing to its high resolution, non-invasive, and fast imaging capabilities. With ongoing technological advancements, the application range of OCT will further expand, providing more powerful tools for scientific research, clinical diagnosis, and industrial production.


Post time: Jun-03-2024