Afocal digital holographic microscopy and its advantages

Applying afocal optical systems in microscopy, especially in digital holographic microscopy (DHM) have several advantages. We have investigated some possible implementations theoretically and experimentally as well. Space bandwidth product of an afocal system can exceed that of the conventional ones. Afocal systems provide higher resolution and much less distortions. Furthermore, the computational cost of the numerical reconstruction and correction phase is also lower in the case of an afocal optical setup, as it ensures constant lateral magnification within the whole measured volume. We show that the advantage of low distortion is especially enhanced in the case of color DHM. GPU implementation of reconstruction software is demonstrated.