Dynamic Fourier-filtering:

Placing the SLM in a Fourier plane it acts as a programmable Fourier filter:

Fig. 2: Generic (off-axis) setup for Fourier-filtering with an SLM.

Toggling between various contrast enhancing techniques, such as bright-field, dark-field, or (spiral) phase contrast microscopy, is as simple and fast as replacing the filter function displayed on the SLM.

Fig. 3: Fourier filtering with SLM: left to right: dark-field, central phase contrast, isotropic spiral phase contrast.


C. Maurer, A. Jesacher, S. Bernet, and M. Ritsch-Marte: What spatial light modulators can do for microscopy, Lasers and Photonics Reviews 5, 81-101 (2011).

S. Fürhapter, A. Jesacher, C. Maurer, S. Bernet, M. Ritsch-Marte: Spiral phase microscopy, Advances in Imaging and Electron Physics 146, 1-20 (2007); Ed. P. Hawkes, Academic Press (ISBN-13: 978-0-12-373908-7).