Real-time High Resolution Optical Coherence Microscopy with a Phase Shifting Apodizer

In conventional optical coherence microscopy (OCM) systems, there is an inherent tradeoff between the depth of focus (DOF) and lateral resolution. A new method to overcome this limitation for real-time optical coherence microscopy is proposed. By simply incorporating a three-zone, pure phase, phase shifting apodizer in a conventional OCM setup, we improve DOF by a factor of 3. A nearly constant lateral resolution of 5.0 mum or better over a depth range of 500 mum is experimentally verified. Since pure phase masks can be easily fabricated and miniaturized, the merits of the proposed method are especially desired in real-time, high-resolution endoscopic OCM systems.