Comparison of two broadband illumination sources in digital lensless holographic microscopy to study biological samples

The use of two broadband illumination sources in digital lensless holographic microscopy (DLHM) is presented. A femtosecond laser and a white light emitting diode, both with spectral widths of hundreds of nanometers, are the optical sources utilized for illuminating biological samples. Despite both sources have similar spectral widths, while the former is fully spatially coherent, the latter is spatially incoherent; this difference determines a completely dissimilar performance of the DLHM. The resulting images of samples obtained with DLHM by using both light sources are analyzed on the framework of basic coherence theory. Sections of the head of a Drosophila Melanogaster fly are imaged with both broadband illumination sources in the digital lensless holographic microscope.