Confocal laser feedback tomography for skin cancer detection

Tomographic imaging of soft tissue such as skin has significant advantages in cancer detection. A confocal approach based on laser feedback interferometry is proposed for noninvasive tomographic imaging at depths penetrable to infrared wavelengths. This compact system uses a semiconductor laser as both transmitter and receiver of the beam and possesses the imaging power of a confocal microscope. We validated the technique on three layer keratinocyte carcinoma phantoms containing macro-structural changes in the optical properties of the second layer. Experimental results agreed with numerical simulations. This work shows the feasibility of a sensitive tomography system for optical imaging of skin.