Self-aligned setup for laser optical feedback imaging insensitive to parasitic optical feedback

We propose a new optical architecture for the laser optical feedback imaging (LOFI) technique which makes it possible to avoid the adverse effect of the optical parasitic backscattering introduced by all the optical interfaces located between the laser source and the studied object. This proposed setup needs no specific or complex alignment, which is why we can consider the proposed setup to be self-aligned. We describe the principle used to avoid the parasitic backscattering contributions that dramatically deteriorate amplitude and phase information contained in the LOFI images. Finally, we give a successful demonstration of amplitude and phase images obtained with this self-aligned setup in the presence of a parasitic reflection. (C) 2008 Optical Society of America