In vivo visualization of dermal collagen fibers in human skin using a photonic-crystal-fiber-coupled, hand-held second-harmonic-generation microscope

Abstract

Second-harmonic-generation (SHG) microscopy is a powerful tool for in vivo monitoring of collagen fibers in human skin. However, its practical use in the dermatological field is still limited due to the bulky and complicated setup. In this paper, we constructed a photonic-crystal-fiber-coupled, hand-held SHG microscope for in vivo monitoring of collagen fibers in human skin. Fiber delivery of ultrashort pulse light was achieved by a large-mode-area photonic-crystal-fiber whereas the SHG microscopy setup was enclosed into a hand-held probe head. The combination of PCF with the hand-held probe head largely enhances the flexibility of measurement sites in the human skin.