Speckle noise mitigation via incoherent averaging in swept-source optical coherence tomography

Speckle noise poses a critical challenge in swept-source optical coherence tomography (SS-OCT), where narrowband, high-coherence light exacerbates granular image artifacts caused by multiple scattering events in tissues. These artifacts limit image quality and diagnostic accuracy. Advancements in silicon photonics have now enabled the compact integration of multi-channel OCT systems, allowing spectrum-incoherent averaging as a practical solution for mitigating speckle noise. In this work, we present a theoretical framework to quantify and simulate speckle-induced noise in SS-OCT images. Our results demonstrate that the incoherent averaging increases the signal-to-noise ratio (SNR) of A-scans by an amount proportional to the square root of the number of compounded signals. By introducing an SNR gain factor into the link budget for multi-channel OCT, this framework provides actionable insights for designing next-generation integrated photonics-based SS-OCT systems for improved image quality and diagnostic performance.