Zichen Yin

1 Introduction The spinal cord, along with the brain, forms the central nervous system, essential for the body's functioning. The spinal cord is a quasi-cylindrical structure, ≈10 to 14 millimeters in diameter, running from the brain down through the vertebral column.[1] Acting like an optical fiber cable, it transmits signals between the brain and the rest of the body, coordinating motor functions, sensory information, and autonomic responses.

Optical coherence tomography (OCT) plays a crucial role in diagnosing corneal diseases due to its capacity to provide high-resolution three-dimensional imaging. However, the convex shape of the cornea and the inherent trade-off between depth of field (DOF) and lateral resolution in OCT systems often result in defocusing issues, leading to reduced lateral resolution and sensitivity in single-shot high-resolution imaging.

Swept laser based on the acousto-optic deflector (AOD) is a promising swept source in optical coherence tomography (OCT) applications for its high wavenumber linear sweep without mechanical motion. However, the poor coherence length and the elongated cavity of the laser imposed limitations on the acquisition of high-quality images with adequate imaging depth and high imaging speed.