Adaptive optical coherence-domain reflectometry using photorefractive quantum wells

Adaptive optical-coherence-domain reflectometry (OCDR) is performed by use of an adaptive interferometer and homodyne detection. The adaptive element of the interferometer is a photorefractive quantum-well device in a two-wave mixing geometry. The mixing self-adaptively maintains constant relative phase between the signal and reference waves and dynamically compensates gross movements of the sample or optical components as well as image speckle. The application described here is used for laser ranging into and through turbid media. Adaptive OCDR is a bridge between conventional optical coherence tomography and adaptive holographic optical coherence imaging. The insertion loss for the adaptive performance is -15 dB, but adaptive OCDR has potential applications for coherence tomography under conditions of large target motion and low background. We also demonstrate its potential application for optoacoustics and laser-based ultrasound detection.