Inspecting and locating foreign body in biological sample by laser confocal feedback technology

Abstract

A promising method is proposed to inspect and locate foreign bodies in biological samples. It combines advantages of confocal microscopy and optical feedback effect of microchip solid-state laser, and retrieves both spatial positioning and specific images by the sensitive detection of extremely weak signals retro-diffused by the interface in samples. By testing onion samples containing pins as foreign bodies, this approach has been demonstrated to examine the foreign body and locate its position within several millimeters depth below the sample surface.