Snapshot Polarized Light Scattering Spectrometric Fiberscopy for Early Cancer Detection

Polarized light scattering spectroscopy (PLSS) is a promising nondestructive method for early cancer detection through capturing single scattered light from the epithelium. A novel fiber-based snapshot PLSS endoscopy capable of collecting single scattered light through a single optical path is introduced. In the endoscope, a simple combination of a fixed multiorder retarder followed by a fixed linear polarizer is proposed at the distal location of multimode fiber for encoding the scattered spectra for the first time. The encoded spectrum is recorded by a fiber spectrometer and subsequently decoded using a compressed sensing (CS) algorithm. The resulting Stokes spectrum S₁ is used to iteratively invert the size of the epithelial nucleus for early cancer detection. As an alternative, the normalized spectrum S₁ is directly weighted for early cancer identification, offering an innovative non-iterative method for rapid diagnosis. A proof-of-concept prototype of the fiber-based snapshot PLSS endoscope is built and its effectiveness is validated through experiments on both tissue physical models and ex vivo gastrointestinal samples.