摘 要：光学相干层析成像（OCT）作为一种非侵入性的高分辨率断层成像技术，其在亚细胞结构及深层组织探测的拓展中对光源性能提出了严苛的要求。超连续谱（SC）光源兼具极宽的光谱覆盖、高空间相干性与优异的时域亮度，构筑了突破传统OCT轴向分辨率极限并支持超高速扫描的核心物理基础。但在实际应用中，非线性展宽过程带来的高相对强度噪声（RIN）会劣化成像信噪比，这成为限制其高灵敏度探测的主要因素。针对这一痛点，近年来研究人员从物理机制［如全正色散（ANDi）架构］和系统层面（如亚像素级平衡探测）入手，有效降低了噪声干扰。这些技术改进不仅使系统在兆赫兹级扫描速率下逐渐向散粒噪声极限靠拢，也进一步开发了其在可见光、短波红外及中红外等波段中的应用潜力。本文重点梳理了SC-OCT在抑制RIN方面的物理机制与架构进展，并在此基础上探讨其在眼底结构及血氧分析、深层组织成像与高散射材料无损检测中的具体应用，以期为相关领域的医学诊断和无损检测技术提供理论参考。
关键词：超连续谱光源；光学相干层析成像；相对强度噪声；医学成像；眼科成像
中图分类号：TN248；R318     文献标志码：A    DOI：10.3969/j.issn.1007-7146.2026.04.002

Abstract: As optical coherence tomography (OCT) is extended toward subcellular and deep-tissue target detection, stringent demands are imposed on light source performance. Characterized by ultra-broad spectral coverage, high spatial coherence, and exceptional temporal brightness, supercontinuum (SC) light sources are established as the core physical foundation for overcoming the axial resolution limits of traditional OCT and enabling ultra-high-speed scanning. Despite these optical advantages, the non-linear broadening process of SC generation inherently introduces high relative intensity noise (RIN). This degrades the signal-to-noise ratio and acts as a primary bottleneck for high-sensitivity imaging applications. Recently, researchers have mitigated this issue through structural innovations, such as all-normal dispersion (ANDi) architectures, and system-level optimizations like sub-pixel balanced detection. These improvements allow SC-OCT systems to operate much closer to the shot-noise limit, even at megahertz scanning rates. Consequently, the detection potential across specific spectral bands—including visible light, short-wave infrared, and mid-infrared—has been substantially expanded. This paper reviews the underlying physical mechanisms and recent architectural advancements in suppressing RIN for SC-OCT systems. Furthermore, we discuss its cross-band applications, ranging from the analysis of fundus microstructures and blood oxygen metabolism to deep-tissue imaging and the non-destructive testing of highly scattering materials, with the aim of providing a theoretical reference for medical diagnosis and non-destructive testing technologies in relevant fields.
Keywords: supercontinuum light source; optical coherence tomography; relative intensity noise; medical imaging; ophthalmic imaging
（Acta Laser Biology Sinica, 2026, 35(4): 298-309）