A handheld PS-OCTA system for simultaneous structural, vascular, and birefringence imaging of human skin

Optical coherence tomography (OCT) is a widely used noninvasive imaging modality for in vivo visualization of skin microstructure with high spatial resolution. As a functional extension of OCT, polarization-sensitive OCT (PS-OCT) enables in vivo mapping of collagen architecture through birefringence and optic-axis analysis, while OCT angiography (OCTA) provides vascular contrast via motion-based signal decorrelation. However, conventional PS-OCT systems are restricted to fixed benchtop configurations and sequential acquisitions, limiting their applicability in point-of-care scenarios and preventing co-registered multi-contrast imaging. Here, we present a compact handheld swept-source PSOCTA system capable of one-shot acquisition of structural, vascular, and birefringence contrasts within a single 10- second volumetric scan. The system operates with a single input polarization state and employs polarization-diverse detection to retrieve depth-resolved Stokes parameters, enabling simultaneous reconstruction of PS-OCT and OCTA datasets. Furthermore, an streamline-based visualization method is developed to intuitively represent local optic-axis orientations, highlighting collagen fiber organization and spatial birefringence heterogeneity across different skin regions. By unifying structural, functional, and polarization-sensitive contrasts into a portable platform, this handheld PS-OCTA system provides a powerful tool for dermatological research and clinical applications, paving the way for accurate, reproducible, and quantitative assessment of skin tissue in vivo. We present a handheld swept-source polarization-sensitive OCT angiography (PS-OCTA) system for in vivo human skin imaging. The system provides co-registered structural OCT, OCTA, and birefringence contrasts in a single volumetric scan, enabling assessment of skin microstructure, microvasculature, and collagen organization. We further use streamline visualization to display collagen fiber trajectories derived from optic-axis orientation, which helps reveal local remodeling patterns in vivo.